I used to replace my impeller two or three times per year. It would only cool the engine if it was brand new. Then I discovered the poppet valve, and have been running the same impeller and running cool since October!
My 92 johnson 150 overheated due to a thermostat. I had just installed a water pressure gauge and felt the motor loose power, looked at the gauge and saw no water pressure. it had melted the line for the pressure gauge. saved my motor for sure. I pulled the thermostats, took it to the ramp slowly and put new ones in. Working great since.
I've seen broken impeller blades stuck inside the water pump housing and inside the water tube. I've blown compressed air into the pee hole and had bits of the old impeller come shooting out. I had some luck using vinegar to clean out corrosion and salt build up in water passages.
I only ever had one time when my motor overheated and it was a doozie. Ended up melting number 3 piston. I can only assume it was a plastic bag picked up while travelling across a dangerous brawny. I guess the bag dislodged once speed was lost but anyway made it back safely thanks to a kicker motor and rebuilt motor.Ran it for a bit the traded it in on another motor.All's well that ends well.Cheers mate and see ya next time.Safe travels and tight lines. Rob
I averted an issue on my 99 Ocean Pro 150. When I was cleaning the engine up for repainting (cowling, lower unit and touch-up on the power head) a small hose nipple on the block crumbled. I traced it to the other end and discovered it was an air bleed to the top of the engine block. It was there to ensure that the voltage regulator which was water cooled on the top of the block remained immersed in cooling water. The passage at the top was blocked with corrosion and I used a piece of wire to ream it out. I replaced the broken nipple on the bottom of the block by the exhaust. I was lucky that I never smoked a regulator.
I have twin 99 Evinrude Ficht 200s on my 89 Stamas 255FF. I haven't put it in the water yet since I bought it. I had to work on through-hull fittings, which were a nightmare, first. Now that I am through that, I am working on engine systems. All control cables are being replaced. I am also going to do a full service on both motors including new plugs, complete cleaning of the cooling system, and a replacement of all thermostats and impellers. I also plan to replace all fuel lines from tank-to-motor, and I will be replacing all fuel filters and lower unit fluid. All that will give me a stake-in-the-ground point for maintenance. I am doing the work myself for all of this. If I could afford someone else to do it, I would have bought a much newer boat! Your videos have helped a lot in showing me what I need to work on. The least I can do is order a shirt. I am even having to use your video on trailer brakes, since mine has none and they are required for registration here in TX.
Hi Thank you so much for this video. Im hoping you can help me with my problem as i have run out of ideas. I have a Yamaha 50 HP 4 stroke outboard F50DET. Motor has been at me for 15 years with no major problems. Used the boat twice this summer with no problems, until a few weeks ago i drove into a bay and reduced the speed, after a few minutes the temperature buzzer sounded, with cool water coming out very well from the tell tail and at a strong pressure. To cut a long story short, i removed the thermostat which was blocked in close position. Still after 4 minutes on idle the temperature buzzer would beep. My mechanic came over removed and cleaned the exhaust plate, changed the impeller and still after 4 minutes on idle the temperature buzzer would beep. We decided to have a look at the cylinder heads, and we found a lot of salt/calcium deposits blocking the bottom part of the bottom cylinder head. Obstructing the water passage way from the cylinder heads to the exhaust plate. Being confident that we solved this problem the mechanic reassembled all parts this morning. Switched on the engine and still on idle after around 5 minutes the temperature buzzer went off. I am honestly out of ideas and desperate to find a solution. Engine is really getting hot especially around the thermostat area. We also tried changing the temperature sensor with a new one but still no change. When i switch in the motor without the thermostat cover water flows out. Any ideas what could be wrong? really appreciate your feedback.
I have same motor and Did the same troublesooting - impeller, thermostat, then removed manifold cover and cleaned. same issue. No fix yet. Next steps - check for stuck open pop it valve and reverse flush the cooling system. People here say this can flush out any broken impeller bits.
Bought my first boat a couple of years ago - just a little canal cruiser with an old Honda 7.5 outboard. I was told when I bought it that the motor had just been fully serviced, so feeling confident, I handed over the money and left the marina, on the start of my 3 day boat trip back home. 20 minutes later and there's only steam coming out of the telltale. I eventually got the engine to an outboard mechanic who gave it the full once-over - the impeller was fine, but all the internal waterways were bunged up, and the thermostat was shot. Couldn't get a replacement 'stat, so it's been bodged permanently open, and never had an overheat problem since.
1999 Tohatsu 70 2-stroke after about 15-16 YEARS running Galveston Bays it would overheat @ WOT. 1 treatment with Rydlyme helped for a bit but ending trying to remove the head to clean out water passages. Snapped #5 head bolt...broke an EZ out and the rescue bit was no help at ALL!. SO I sold the boat after 20 years and purchased another : )
Good video about the water pumps. I sent a email last week about parts of a impeller that traveled up the water tube and got stuck blocking the water flow. Had to pull the power head to find the blockage. Customer had taken it to 2 different shops. None could find the problem. I guess that why they bring the tuff stuff to me :) From "Frosty' Boat Works" Rhinelander, Wis.
Descaled my 97 yam 150 at 900hrs. Pulled tstats and lower unit, rigged a cheap bilge pump to the pickup tube with a piece of garden hose. Put the pump in a 5gal bucket of rydlyme solution setting the pump on a brick a few inches higher in the bottom of the bucket, hooked it to a battery and circulated that solution for about 4hrs. I got an inch of solids in the bottom of the bucket when it was done!! Inside the thermostat holes it went from crusty to clean! So I assume inside the block did the same. Use Salt Away every flush since
I work on a 2004 Yamaha F225. When on dry dock is doesn't get enough flow through the ears or static hook up. I have great water pressure on my hose. I had to use a 55 gallon drum to get it to cool correctly while working on it. On the water, it works fine.
I've been chasing an overheat issue for two weeks. I bought a 2006 Mercury 115 EFI four stroke off Craigslist that the previous owner said had been rebuilt at a shop and sold to him. Before my first use I changed the water pump including the housing, and noticed that the old impeller was intact. It ran fine and peed at idle, but when I took it out on the water the first time within five minutes at quarter throttle the overheat alarm sounded. Changed the thermostat, back out, same thing - alarm. Ran Barnacle Buster through it on a loop with a spare bilge pump and hose for four hours to eliminate salt/corrosion, ran on the lake again, alarmed again. Checked thermosensor and oil switch, both were fine. Took off the exhaust access plate and found a piece of rubber impeller blocking one of the intake passages from the water tube. Removed it, buttoned up the plate, took it back out on the water, still getting alarm. Now I'm convinced there are other pieces of impeller in the water tube (I don't want to contemplate there are pieces in the engine block cooling passages) and today will find contraptions to snake out the water tube (it has three bends in it so it is hard to get anything up in it that is strong enough to pull pieces out). All this means that the guy who sold it to me with an intact water pump impeller must have known that it was overheating when he sold it. Wish me luck.
At 6:48 it looks like the top thermostat has no water coming out and the otherside the bottom thermostat didnt either. But the other two thermostats did. Does that mean there was a problem with this engine's cooling?
I have a 50 mercury on a 14ft flat bottom aluminum boat and I was doing my yearly checks and noticed it wasn’t flowing. Pulled the tell tale hose and there was a small rock jammed in the hole. Removed that and still nothing through the hose. Blew it out with air and found that a spider had built a nest in the hose.
Hi all, I have a Tohatsu 115 TLDI which have had heating problem during long time since all removable components seem fine. After brave attempts, I figured out that the water feed tube, that is routing water from water pump to the engine block, is heavily deformed at the engine block side and there left very little space allowing water pass through. I have changed the tube with a new one, and the problem has been resolved. That requires me to remove engine block from the outboard though, which was a very scary task for an amateur like me.
One very important point missed which was the reason for my overheating was not running the engine the the sea while testing for errors. The water level was not high enough although it fully flooded the inlet valve. Moreover, isn't insufficient oil or oil mixed up with water another reason. Thanks for the video, I wish it was out earlier as I was facing this issue and went through weeks of stress trying to find out the water cycle in the engine
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I had a Mercury 175HP Pro XS in my Workshop about 2 years that was getting hot. It had a really good tell tale and the customer said the impeller was changed only about 4 months before. The problem ended up being the impeller which had actually split at the hub area. The hub was still fairly well bonded to the impeller except on one side of the split an area of 1.5cm was unbonded. I suspect that the impeller vanes must have been stuck to the stainless pump liner and when the motor was started it caused the impeller to split.
I had a near disastrous outing last year..blackmax 150 was losing power and i looked at temp gauge which was very high..i closec off power and turned off engine...left it to guy does my work..got it back, it had real good tell tail, solid...put into storage over winter..getting ready today to take out this weekend and tell tail isnt the same..,still good but not that solid steel bar effect Any1 any ideas? Tia
@@brendanbrendan6721 It could be debris in the tell tale restricting the flow. Try blowing some compressed air in the tell tale - do it both whilst the motor is stopped and when it's running. It could be that the impeller has lost some tension from sitting over winter.
I got my first boat at the beginning of this year (1991 scout with 1993 yamaha 130)I bought the water pump repair kit for preventative maintenance that comes with housing, impeller, gaskets, etc, but didnt realize there is a seal that connects to the top of water pump housing that the kit didn't include. Engine kept overheating til I Learned to always compare the old parts with the new parts lol.
My 200 merc 2 stroke overheated 1 month after a new impeller was installed, had to be towed. I did the work myself and was baffeled. So I put it in shop as I wanted him to take care of another issue. Low and behold he showed me the impeller and the hub had spun out letting me off the guilty throne. He also said he had only seen that once before. Thank god for Boat USA insurance I might add. Thanks I needed that video...
My Mercury 75hp2 stroke is giving me an overheating alarm when run at 3800 RPM and above but didn't sound the alarm once kept below 3800rpm. The impellers is new and seem to be pumping strong and the thermostat and the poppet valve diaphragm is brand new.
I changed the thermostats put a new water pump kit and poppet valve in the old two stroke I bought and I'm glad I did. The thermostats were corroded and the poppet valve diaphragm was shot. The water pump looked brand new but changed it anyway. Now I know why the over heat sensor was disconnected.
Our VFD's rescue boat(an early 2000's bay boat) has a 200 Evinrude H.O.(gen1) on it, and has been having trouble over heating. The last couple times it happened, the mechanic blamed it on "towing too fast" with it. Well it happened on our last rescue call, and I was driving. Water was stupid rough, so we were moving at a high idle. The boat was loaded down with water(it's really not meant for rough water), so I reckon it could have been such an issue, but I couldn't find any evidence of insufficient flow. Gonna be using advice from this video in checking it out. Thanks!
I think you should also mention that on a sterndrive if the dive is stored in the up position the hose in the drive going toward the engine can develop a kink, Then in the spring when you lower the drive to run the hose is restricted and will overheat at higher RPM, but look fine at idle and low speeds.
I just rebuilt a Yamaha F100TLRA which had spun a rod bearing believed due to neglected oil or cold start abuse, and on initial break in test (with the water hose fitted, not on the water) had an issue with overheat alarm coming on when idling for a few mins! With the engine running at half throttle continuously for 20min, no alarm. reduced throttle to 10% but still in gear, alarm also came on after a few min. if alarm was on, it would not turn off if accelerated, but I only tested that for a few seconds so as not to damage the engine. it was shut off each time and on restart, no more alarm. if idling, would alarm within a few mins. I found that the tell tail restrictor is missing, and my assumption is that the cooling system on this engine will overheat without the tell tale restriction at idle due to lack of coolant jacket pressure. I think that the impeller can't generate enough psi without the restrictor and the water around the cylinders starts to boil or otherwise slowly drain out of the jacket leaving the engine to overheat when idling. I will test various scenarios with a restrictor in place.
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2012 Yamaha F250 Idle over heat and low RPM over heat, as long as I'm running 1000+RPM its fine. New water pump and housing, new Pop valve and thermostats. Pulled anodes from the block and they looked great, and ran water while the stats and anodes were out and had good water flow, still over heats at idle. Guess its time for the pros to look at it, lol
Great video! When you were checking if water was flowing out of the open thermostats what hose were you running the garden hose water through? I have a Suzuki df70 and water doesn't seem to be getting up to the thermostat. Telltale is pissing water on muffs so I don't think it's the impeller. I love your channel!
Sometimes the muffs can lose your pressure, i had it hooked up to the flush port on the side of the engine and did it without running the engine. See if that helps and gets the water to come out
I am taking a preventative measure and descaling my engine. I’m pulling the thermostats and the anodes. Gonna run rydlyme through the water pickup tube. Ever done this @bornagainboating? Curious to know what descaling solution you would use?
I think you would be fine with just running the saltaway once or twice a year! Then pulling out the thermostats and anodes and checking them every other year, the thermostats more often than the anodes. Anodes maybe once every two years and the thermostats maybe once a year, depending on how you use your boat and where you are located ;)
I did this to my 97 yam 150 at 900hrs. Pulled tstats and lower unit, rigged a cheap bilge pump to the pickup tube with a piece of garden hose. Put the pump in a 5gal bucket of rydlme solution setting the pump on a brick a few inches higher in the bottom of the bucket, hooked it to a battery and circulated that solution for about 4hrs. I got an inch of solids in the bottom of the bucket when it was done!! Inside the thermostat holes it went from crusty to clean! So I assume inside the block did the same. Use Salt Away every flush since
First thing i do when i get a motor is get a manual. Learn how it works and how to take care of it. like high grade filters and de-scaleing . keep any problems from happening.
Had an old Nissan 70hp that would only over heat at WOT for a min or 2. Turned out being some buildup in the heads. Had em pulled and cleaned and ran great ever since
Hello My marine superchager 300 engine it’s displayed on acreen supercharger over heated. I did change the sensor and still over heated on high speed only Looking for your advice Thank you
I had an I/O overheat from Ice in the water pipe coming out of the leg on a 60* January day. It resolved after a few minutes sitting in the water melted the Ice.
As always, your videos are second to none - they are more like tutorials. I remember back in the day when i didn't know anything about boating, I had a 2000 Mercury 150 which would overheat at low RPMs. Clearing any channel was a stressful experience because the alarm would go off.. After researching i learned the poppet valve could have been the culprit so i changed it and that fixed my issue.
I had a mercury 7.5 that was my first motor. I bought it and was so stupid but did not see if it was pissing water. So I took it out and it overheated, brought it home and changed the impeller, nothing. It didn’t have a thermostat so I didn’t have to worry about that. I asked around and came to the conclusion there was a blocked passage way so I blew air through and nothing. I took the engine block off and turns out a little o ring like thing was melted and clogging the water passage. I checked every marine store around and found one that had been on the shelf for over 20 years 😂
Eman Kosak whenever I’m working on some old or obsolete machine or equipment I always think that to myself. Somewhere in this world there’s a part for this in a dusty warehouse sitting on a shelf for twenty something years. Now am I able to find it? 🤔
Great info! Thank you. I’m not sure if my 1990 Johnson 70 2 stoke has a poppet valve. Anyone know if it does? I haven’t seen anything like it after multiple hours of working on her.
Not sure, I just looked at boats.net and didn't see one. (I just did a quick scan) it might not, a lot of the small engines don't have them because they don't need them. A 70's right there in the middle, it's not really a small engine, but it's not a big engine :) Those 50-115's are all mid-range engines like that.
Yes it should be like this one epc.brp.com/Index.aspx?lang=E&s1=25d5e0b4-1d47-4c2d-9a21-cdca06192200 The vernatherm (thermostat) is in a plastic housing which incorporates a an external Spring thus acting as a relief/poppet valve. A lot of the Johnson/Evinrude Poppet valves are actually set up like this.
2011 F25 overheat alarm came on .. boat slowed down … engine was pissing but was hot . Not normal … luckily made it back to land moving real slow and turned engine off . Could this be a thermostat issue as it was in idle in shallow water before the boat left land . No debris found in the foot
I brought a 14ft 79 fleetline sapphire mk4 with a 85hp Mercury Blueband. I've just done a compression test and found all 4 cylinders running under 100psi the impeller housing melted with 3 missing fins I'm a full novice that is going to attempt to strip and rebuild
J Glez sorry I can’t video the item however a quick search of UA-cam specific for “poppit” should turn up several sources like ua-cam.com/video/SQdFHiMgkKM/v-deo.html
Yes it is especially if the engine is going to sit for aa while before it used again. I recommend running the engine for a least five minutes on a flusher.
I have a 150 hp mercury the engine works very well in fact last weekend we sailed 100 miles and had no problem, but when I leave it on low the engine temperature increases to about 200 gf, the engine was 10 years without use, for It's pretty clogged inside. Can you recommend a good chemical to wash the inside of the engine? thank you so much
Have a 92 v6 Yamaha that would overheat above 4000 rpms. Pulled the heads to find most passages completely clogged. Cleaned em all out and havent had an overheat since.
Hey big fan of the content. I recently made a big mistake. I flushed my engine with a hose that was loaded with sand on my 05 yahama 115. I was able to unclog the pee hole but now there isn't really any water getting down to the lower unit out the screens. Looking for suggestions to flush the sand out in the system. Thanks!
I have a2014 Yamaha 40hp four stroke cylinder and I have replaced both thermostat and impeller the replaced the thermostat thinking it was bad because I thought it wasn’t letting water to run through it and when took off and ran the engine water came out so that means the impeller is working I took off the tattletale hose and cleaned it out there was nothing inside the hose and it was dry need help where else could I look
This is perfect timing! I was coming back to the dock from a day of fishing on Sunday and at idle I started getting an overheat condition so I turned off the motor and I had to keep putting around in order for the engine to stay cool but every time I sat at idle it kept overheating. Last time that happened to it was the waterpump impeller but this one only has less than 60 hours on it. Could it be a thermostat? Thanks! 2013 Yamaha F150
I pulled it and it still looks good! No sand or gunk on it. A little bit of green corrosion checked the temp specs in a boiling pot. How often do you recommend changing thermostats? This one has about 500 hours on it
Once again you guys have taught me a thing or two when I thought I had it down. Specifically the number of items in an outboard that can be water cooled. I knew about superchargers but nothing else. I've always gone by the notion that as long as the outboard is vertical all water will drain. This is very important for boater's in northern climates but maybe it doesn't always hold true? Do some outboard's have drain plugs that need opening for winterizing to ensure all water is out?
mercruiser 470 overheated bc of an airlock in the coolant system after a full drain bc i had to install a new starter. a vid about how to install an i/o engine temp alarm would be greatly appreciated. thanks for the vids
Hi guys, I just bought a 1982 Johnson 150hp v6. They said it ran fine, but when I pulled the thermostat housing I noticed that it didn't have any, also they had two different springs for the pop it valves. I also found that the top carburetor didn't have the retaining clip to hold the needle to the float. So the top needle looked brand new while the other two showed signs of wear. Checked compression and it was low and all over the show. Heads were a little warped, just had them skimmed. So I definitely reckon that it had majorly over heated. Do you have any other thoughts on why they soul have or why they had to do this. Cheers and thank you for channel, love your content. Sav, Australia.
Cheers, I'll wait and see when the new gaskets arrive. Hopefully it's going to be a good motor. Was planning on fitting it to my 1982 15ft half cabin cruiser. I have completely rebuilt this boat. From adding more glass to the whole hull, new stringers, new bigger and stronger transom and floor. She should be bullet proof. Love your work keep it up. Cheers from the land down under.
I have a 2015 Yamaha 150 that has intermitent overheating only when out of the water while flushing, with muffs or a large trash can of water. Just had the impleller relaced, and thermostat looked at by my service guy. Took the boat out last weekend, ran fine and cooled fine with good telltail. Got home and was flushing and no telltale, and began to over heat. With muffs and in the trash can with water. Couple of weeks ago, I did get in shallow water with sand, over heated, service guy pulled pump apart and found impeller in pieces. Was replaced and ran great, but for some reason when flushing I get no cooling our tell tale. Thermostat area seems fine, no sand, but a small amount of corrosion. I'm going to pull thermostat off again today to see if I get flow there. Could there be some sort of other blockage?? Frustrating! Any ideas?
It's not uncommon, it's the backpressure and water issue. You just don't have enough hose pressure and even being in a trash can, sometimes it's not enough pressure. A lot of outboards will have trouble running on hose and can overheat after a couple of minutes of running. You might be chasing a rabbit that doesn't exist :/ are you just totally against flushing from the flush attachment without running the engine?
Saltaway and good water pressure, but you'll want to pull the thermostats and anodes to let the water push the stuff out. Otherwise you have to pull the heads and other components to clean them out manually.
@@BornAgainBoating thanks! If there are multiple thermostats, does it help to remove one at a time in order to provide better pressure to one half of the cooling system while flushing?
I am fan of Salt-a-way / Salt Terminator. I religiously flushed a ski with those products and after several years and 450+ hours later, the water jackets in the manifold looked brand new 👍🏻 Have you had success with using a descaling product on neglected motors?
Salt away is a great product! But on the neglected engines, if it gets to the point where it comes to us, we take them apart and physically clean them, but a lot of the times it was neglected until it blew up! So, I don't have a lot of experience with many descaling products lol :/
My 1998 Yamaha 150 2 stroke is acting like its overheating. It runs fine for a few minutes under load then goes into reduced RMP mode. I've cleaned the water channels, replaced the impeller, replaced the thermostats, replaced the cylinder and water jacket gaskets, and replaced both thermo sensors. I'm going to take the poppet valve off tomorrow and examine it. I shot the cylinders with a temp gun. The left side is running at 150 F and the right at 200 F at idle with the muffs on. Don't know if that's normal or not.
😱😱 oh man seeing those saltwater used t-stats and cooling passages feels like a horror movie to me, who runs freshwater a couple of weekends a year lol😆
I have 2 Yamaha 250 hp 4 stroke engines on my boat Recently, we had water shortage in the marina where my boat is, and flushing was erratic for about a month. I noticed that the temp of engines started to show erratic readings, instead of being in the middle range as it was always, it started going up and down but no overheating. I asked the technician I deal with to take the boat out, change all 4 thermostat and both engines' puppet valves along with overdue replacement of the engines' anodes. Your video is really educational for those who know or don't know about the tech. stuff about outboards. Big Thanks
have you ever seen boat owners using a product such as Salt away and noticed any difference with less salt buildup? thanks Aaron great video sir! I've got 1 Mercruiser closed loop, and 3 outboards my 470 Mercruiser needs water circulation pump replaced :( :( switching to all outboards sooner than later haha!!
Yes, salt away does keep the cooling passages cleaner. But you only need to do it a couple times a year depending on how you use your boat :) thank you and outboards are definitely easier to mess with lol :)
@@BornAgainBoating my outboard is over heating strangely the pee stream runs hot then cold then hot and back to cold each time the heat comes back around it gets voter than the time before till it all just steam?any ideas
I'm not a boater but interesting engineering interests me and outboard motors are very interesting. Check out the videos of Malcolm Oastler. He put a two-stroke Merc V6 in a motorcycle. He modified the poppet valve cover to be the coolant inlet from the radiator. There is an oddly shaped passage to the right of the exhaust passages (the engine is mounted horizontally with the cylinders down) that is the hot coolant outlet to the radiator. He claimed that the water cooled divider plate in the exhaust cavity is now uncooled. I will never have the resources to have a two-stroke V6 put into an old, lightweight vehicle but Mal's videos are lacking in clearly explaining some of his decisions and I'd like to have a better understanding of those decisions. So... If an expert on the Mercury design would wade through Mal's playlistless videos to find the ones that address the cooling system and critique Mal's decisions that would be greatly appreciated.
No, small engines usually don't. Every brand is different, but for the most part, once you get above say 90 HP almost all do, but then like 70's and below, some do and some don't. The small engine has a small block and head, doesn't take much water to fill them up so the valve isn't needed :)
I have a 06 evinrude 250 that is melting the exhaust pipe and water pump housing I replaced thermostat and followed the wather and not clogs found any ideas?
two reasons why impellers are made of rubber not brass. 1. if solid debris such as mud get into the pump, rubber impeller will pass it through while brass impellers will not and would cause the impeller to jam up. 2. The pump housing is not quite circular in shape, thus the rubber impeller. That is my humble opinion :)
@@nayefalhajri7927 the "center" of the water pump is off center, causing the fins to compress on one side and expand on the other, thereby creating the pressure to pump the water. Rubber flexes to create that offset pressure..
Ouch! Probably not because of over heating, but because of a blown gasket somewhere. You'll need to figure out where the water is coming from before doing anything else. You don't want to cause more damage to the engine by running it like that and letting it blow up!
Great video . I’m running a 2 stroke 1990 Evinrude 60. I’m currently trying to trouble shoot if it is fuel issue or overheating. My boat will start up and run fine for a good little while. After stopping to fish for awhile , it refuses to fire back up. I crank and crank with no turn over. Wondering if anyone else has dealt with this? Going to change the impeller regardless since I just got the boat. Any help would be appreciated.
Could be overheating, but make sure its not loosing fuel by an air leak in the system, try priming the bulb after you stop and see if it gets fuel and starts
Bought a boat with a 1984 115 hp evinrude overheating Pulled the pump and it was clogged 75% with sealant some the guy getting crazy with it stuck one of the plastic by pass with spring things that goes to one side of the motor crazy
Yamaha 60tlrz. Will throw overheat alarm after idling for a while or idling after running wot. Changed temp sensor, thermostat, impeller, then rebuilt whole water pump with new impeller, tested thermostat and temp sensor on stove with hot water, pulled head and exhaust cover to check for blockages. Everything clean. 98% sure this model does not have a poppet valve. I just can't build enough water pressure to keep it cool at idle. Very annoying.
I just rebuilt a Yamaha F100TLRA which had spun a rod bearing, and on initial break in test (with the water hose fitted, not on the water) I also had an issue with overheat alarm coming on when idling for a few mins! with the engine running at half throttle continuously for 20min, no alarm. reduced throttle to 10% but still in gear, alarm also came on after a few min. if alarm was on, it would not turn off if accelerated, but I only tested that for a few seconds so as not to damage the engine. it was shut off each time and on restart, no more alarm. if idling, would alarm within a few mins. I found that the tell tail restrictor is missing, and my assumption is that the cooling system on this engine will overheat without the tell tale restriction at idle due to lack of coolant jacket pressure. I think that the impeller can't generate enough psi without the restrictor and the water around the cylinders starts to boil or otherwise slowly drain out of the jacket leaving the engine to overheat when idling. I will test various scenarios with a restrictor in place.
I have over heat engine and not water coming out port turn out was impeler get to the marina after boat us tow my boat take lower unit off and replaced and 1/2 hour later back in the whater finish up the good day fishing
HOT TIP; I Started and Ran a 175 hp merc outboard on a trailer and without water! 3 seconds and shut it down. Water Cooler Impeller ; disintegrated. Define; weekend shot?
@@eamh2002 famous last words bro; without any exaggeration. Nylon??? Perhaps titanium would be best? Turned my $12000.00 merc out board into a very noisy marshmellow roaster.
I have an older Johnson 120 vro that is making this beeping sound from time to time. The constant beep is coming from the console. Any ideas on what it may be?
I used to replace my impeller two or three times per year. It would only cool the engine if it was brand new. Then I discovered the poppet valve, and have been running the same impeller and running cool since October!
I'm new to boating and this channel has been a godsend for me. Thanks.
Welcome aboard!
My 92 johnson 150 overheated due to a thermostat. I had just installed a water pressure gauge and felt the motor loose power, looked at the gauge and saw no water pressure. it had melted the line for the pressure gauge. saved my motor for sure. I pulled the thermostats, took it to the ramp slowly and put new ones in. Working great since.
I've seen broken impeller blades stuck inside the water pump housing and inside the water tube. I've blown compressed air into the pee hole and had bits of the old impeller come shooting out. I had some luck using vinegar to clean out corrosion and salt build up in water passages.
I only ever had one time when my motor overheated and it was a doozie. Ended up melting number 3 piston. I can only assume it was a plastic bag picked up while travelling across a dangerous brawny. I guess the bag dislodged once speed was lost but anyway made it back safely thanks to a kicker motor and rebuilt motor.Ran it for a bit the traded it in on another motor.All's well that ends well.Cheers mate and see ya next time.Safe travels and tight lines. Rob
I averted an issue on my 99 Ocean Pro 150. When I was cleaning the engine up for repainting (cowling, lower unit and touch-up on the power head) a small hose nipple on the block crumbled. I traced it to the other end and discovered it was an air bleed to the top of the engine block. It was there to ensure that the voltage regulator which was water cooled on the top of the block remained immersed in cooling water. The passage at the top was blocked with corrosion and I used a piece of wire to ream it out. I replaced the broken nipple on the bottom of the block by the exhaust. I was lucky that I never smoked a regulator.
I have twin 99 Evinrude Ficht 200s on my 89 Stamas 255FF. I haven't put it in the water yet since I bought it. I had to work on through-hull fittings, which were a nightmare, first. Now that I am through that, I am working on engine systems. All control cables are being replaced. I am also going to do a full service on both motors including new plugs, complete cleaning of the cooling system, and a replacement of all thermostats and impellers. I also plan to replace all fuel lines from tank-to-motor, and I will be replacing all fuel filters and lower unit fluid. All that will give me a stake-in-the-ground point for maintenance. I am doing the work myself for all of this. If I could afford someone else to do it, I would have bought a much newer boat!
Your videos have helped a lot in showing me what I need to work on. The least I can do is order a shirt. I am even having to use your video on trailer brakes, since mine has none and they are required for registration here in TX.
Awesome! Congrats on the boat and thank you!
Hi Thank you so much for this video. Im hoping you can help me with my problem as i have run out of ideas. I have a Yamaha 50 HP 4 stroke outboard F50DET. Motor has been at me for 15 years with no major problems. Used the boat twice this summer with no problems, until a few weeks ago i drove into a bay and reduced the speed, after a few minutes the temperature buzzer sounded, with cool water coming out very well from the tell tail and at a strong pressure. To cut a long story short, i removed the thermostat which was blocked in close position. Still after 4 minutes on idle the temperature buzzer would beep. My mechanic came over removed and cleaned the exhaust plate, changed the impeller and still after 4 minutes on idle the temperature buzzer would beep. We decided to have a look at the cylinder heads, and we found a lot of salt/calcium deposits blocking the bottom part of the bottom cylinder head. Obstructing the water passage way from the cylinder heads to the exhaust plate. Being confident that we solved this problem the mechanic reassembled all parts this morning. Switched on the engine and still on idle after around 5 minutes the temperature buzzer went off. I am honestly out of ideas and desperate to find a solution. Engine is really getting hot especially around the thermostat area. We also tried changing the temperature sensor with a new one but still no change. When i switch in the motor without the thermostat cover water flows out. Any ideas what could be wrong? really appreciate your feedback.
I have same motor and Did the same troublesooting - impeller, thermostat, then removed manifold cover and cleaned. same issue. No fix yet. Next steps - check for stuck open pop it valve and reverse flush the cooling system. People here say this can flush out any broken impeller bits.
Bought my first boat a couple of years ago - just a little canal cruiser with an old Honda 7.5 outboard. I was told when I bought it that the motor had just been fully serviced, so feeling confident, I handed over the money and left the marina, on the start of my 3 day boat trip back home. 20 minutes later and there's only steam coming out of the telltale. I eventually got the engine to an outboard mechanic who gave it the full once-over - the impeller was fine, but all the internal waterways were bunged up, and the thermostat was shot. Couldn't get a replacement 'stat, so it's been bodged permanently open, and never had an overheat problem since.
1999 Tohatsu 70 2-stroke after about 15-16 YEARS running Galveston Bays it would overheat @ WOT. 1 treatment with Rydlyme helped for a bit but ending trying to remove the head to clean out water passages. Snapped #5 head bolt...broke an EZ out and the rescue bit was no help at ALL!. SO I sold the boat after 20 years and purchased another : )
Good video about the water pumps. I sent a email last week about parts of a impeller that traveled up the water tube and got stuck blocking the water flow. Had to pull the power head to find the blockage. Customer had taken it to 2 different shops. None could find the problem. I guess that why they bring the tuff stuff to me :)
From "Frosty' Boat Works" Rhinelander, Wis.
Good explanation, especially about the poppet valve. I wasn’t sure what it’s exact function was. Now I know.
Glad you liked it!
Descaled my 97 yam 150 at 900hrs. Pulled tstats and lower unit, rigged a cheap bilge pump to the pickup tube with a piece of garden hose. Put the pump in a 5gal bucket of rydlyme solution setting the pump on a brick a few inches higher in the bottom of the bucket, hooked it to a battery and circulated that solution for about 4hrs. I got an inch of solids in the bottom of the bucket when it was done!! Inside the thermostat holes it went from crusty to clean! So I assume inside the block did the same. Use Salt Away every flush since
I have found that prune juice helps to keep things moving, and beer keeps the tell tale flowing
😂
I work on a 2004 Yamaha F225. When on dry dock is doesn't get enough flow through the ears or static hook up. I have great water pressure on my hose. I had to use a 55 gallon drum to get it to cool correctly while working on it. On the water, it works fine.
Merc 225 EFI run on the hose is ok until you turn it off and then indicates an over heat. I'm guessing it doesn't like the hose.
2001 Yamaha 150 carbed, low rpm overheat, fixed it with a new poppet, never heard of one before!
I've been chasing an overheat issue for two weeks. I bought a 2006 Mercury 115 EFI four stroke off Craigslist that the previous owner said had been rebuilt at a shop and sold to him. Before my first use I changed the water pump including the housing, and noticed that the old impeller was intact. It ran fine and peed at idle, but when I took it out on the water the first time within five minutes at quarter throttle the overheat alarm sounded. Changed the thermostat, back out, same thing - alarm. Ran Barnacle Buster through it on a loop with a spare bilge pump and hose for four hours to eliminate salt/corrosion, ran on the lake again, alarmed again. Checked thermosensor and oil switch, both were fine. Took off the exhaust access plate and found a piece of rubber impeller blocking one of the intake passages from the water tube. Removed it, buttoned up the plate, took it back out on the water, still getting alarm. Now I'm convinced there are other pieces of impeller in the water tube (I don't want to contemplate there are pieces in the engine block cooling passages) and today will find contraptions to snake out the water tube (it has three bends in it so it is hard to get anything up in it that is strong enough to pull pieces out). All this means that the guy who sold it to me with an intact water pump impeller must have known that it was overheating when he sold it. Wish me luck.
What a asshole .. good luck man
At 6:48 it looks like the top thermostat has no water coming out and the otherside the bottom thermostat didnt either. But the other two thermostats did. Does that mean there was a problem with this engine's cooling?
No, that was actually water coming out of the abode holes and the lack of water was because of water pressure
I have a 50 mercury on a 14ft flat bottom aluminum boat and I was doing my yearly checks and noticed it wasn’t flowing. Pulled the tell tale hose and there was a small rock jammed in the hole. Removed that and still nothing through the hose. Blew it out with air and found that a spider had built a nest in the hose.
Hi all, I have a Tohatsu 115 TLDI which have had heating problem during long time since all removable components seem fine. After brave attempts, I figured out that the water feed tube, that is routing water from water pump to the engine block, is heavily deformed at the engine block side and there left very little space allowing water pass through. I have changed the tube with a new one, and the problem has been resolved. That requires me to remove engine block from the outboard though, which was a very scary task for an amateur like me.
Thanks some people you can't run on flush hose but I like your post so I will try it thanks again kept. Up the good pots you do
One very important point missed which was the reason for my overheating was not running the engine the the sea while testing for errors. The water level was not high enough although it fully flooded the inlet valve. Moreover, isn't insufficient oil or oil mixed up with water another reason. Thanks for the video, I wish it was out earlier as I was facing this issue and went through weeks of stress trying to find out the water cycle in the engine
If a good flow of water is pissing out of the engine , does that rule out the impeller and water pump? Thanks
Thank you for your question! Please post it in our Born Again Boating Community! Go here and scroll down to access - it’s free: www.bornagainboating.com/
I had a Mercury 175HP Pro XS in my Workshop about 2 years that was getting hot. It had a really good tell tale and the customer said the impeller was changed only about 4 months before. The problem ended up being the impeller which had actually split at the hub area. The hub was still fairly well bonded to the impeller except on one side of the split an area of 1.5cm was unbonded. I suspect that the impeller vanes must have been stuck to the stainless pump liner and when the motor was started it caused the impeller to split.
I had a near disastrous outing last year..blackmax 150 was losing power and i looked at temp gauge which was very high..i closec off power and turned off engine...left it to guy does my work..got it back, it had real good tell tail, solid...put into storage over winter..getting ready today to take out this weekend and tell tail isnt the same..,still good but not that solid steel bar effect
Any1 any ideas? Tia
@@brendanbrendan6721 It could be debris in the tell tale restricting the flow. Try blowing some compressed air in the tell tale - do it both whilst the motor is stopped and when it's running. It could be that the impeller has lost some tension from sitting over winter.
Recently bought an etec 225hp that overheated first time out. Faulty installed water impeller and telltale back pressure valve missing.
I got my first boat at the beginning of this year (1991 scout with 1993 yamaha 130)I bought the water pump repair kit for preventative maintenance that comes with housing, impeller, gaskets, etc, but didnt realize there is a seal that connects to the top of water pump housing that the kit didn't include. Engine kept overheating til I Learned to always compare the old parts with the new parts lol.
Nice work!
My 200 merc 2 stroke overheated 1 month after a new impeller was installed, had to be towed. I did the work myself and was baffeled. So I put it in shop as I wanted him to take care of another issue. Low and behold he showed me the impeller and the hub had spun out letting me off the guilty throne. He also said he had only seen that once before. Thank god for Boat USA insurance I might add. Thanks I needed that video...
Happy to help man!
Great video Aaron! I had to change my mercury 200HP offshore 2 stroke poppet valve and thermostats.
My Mercury 75hp2 stroke is giving me an overheating alarm when run at 3800 RPM and above but didn't sound the alarm once kept below 3800rpm. The impellers is new and seem to be pumping strong and the thermostat and the poppet valve diaphragm is brand new.
I'd make sure it is an overheat alarm and check the actual sensor
I changed the thermostats put a new water pump kit and poppet valve in the old two stroke I bought and I'm glad I did. The thermostats were corroded and the poppet valve diaphragm was shot. The water pump looked brand new but changed it anyway. Now I know why the over heat sensor was disconnected.
Our VFD's rescue boat(an early 2000's bay boat) has a 200 Evinrude H.O.(gen1) on it, and has been having trouble over heating. The last couple times it happened, the mechanic blamed it on "towing too fast" with it. Well it happened on our last rescue call, and I was driving. Water was stupid rough, so we were moving at a high idle. The boat was loaded down with water(it's really not meant for rough water), so I reckon it could have been such an issue, but I couldn't find any evidence of insufficient flow. Gonna be using advice from this video in checking it out. Thanks!
Keep us posted!
I think you should also mention that on a sterndrive if the dive is stored in the up position the hose in the drive going toward the engine can develop a kink, Then in the spring when you lower the drive to run the hose is restricted and will overheat at higher RPM, but look fine at idle and low speeds.
I just rebuilt a Yamaha F100TLRA which had spun a rod bearing believed due to neglected oil or cold start abuse, and on initial break in test (with the water hose fitted, not on the water) had an issue with overheat alarm coming on when idling for a few mins! With the engine running at half throttle continuously for 20min, no alarm. reduced throttle to 10% but still in gear, alarm also came on after a few min. if alarm was on, it would not turn off if accelerated, but I only tested that for a few seconds so as not to damage the engine. it was shut off each time and on restart, no more alarm. if idling, would alarm within a few mins. I found that the tell tail restrictor is missing, and my assumption is that the cooling system on this engine will overheat without the tell tale restriction at idle due to lack of coolant jacket pressure. I think that the impeller can't generate enough psi without the restrictor and the water around the cylinders starts to boil or otherwise slowly drain out of the jacket leaving the engine to overheat when idling. I will test various scenarios with a restrictor in place.
Thank you for your question! Please post it in our Born Again Boating Community! Go here and scroll down to access - it’s free: www.bornagainboating.com/
2012 Yamaha F250 Idle over heat and low RPM over heat, as long as I'm running 1000+RPM its fine. New water pump and housing, new Pop valve and thermostats. Pulled anodes from the block and they looked great, and ran water while the stats and anodes were out and had good water flow, still over heats at idle. Guess its time for the pros to look at it, lol
Yeah, there's something missing somewhere lol some investigation needing to be done there!
Great video! When you were checking if water was flowing out of the open thermostats what hose were you running the garden hose water through? I have a Suzuki df70 and water doesn't seem to be getting up to the thermostat. Telltale is pissing water on muffs so I don't think it's the impeller. I love your channel!
Sometimes the muffs can lose your pressure, i had it hooked up to the flush port on the side of the engine and did it without running the engine. See if that helps and gets the water to come out
I am taking a preventative measure and descaling my engine. I’m pulling the thermostats and the anodes. Gonna run rydlyme through the water pickup tube. Ever done this @bornagainboating? Curious to know what descaling solution you would use?
I think you would be fine with just running the saltaway once or twice a year! Then pulling out the thermostats and anodes and checking them every other year, the thermostats more often than the anodes. Anodes maybe once every two years and the thermostats maybe once a year, depending on how you use your boat and where you are located ;)
I did this to my 97 yam 150 at 900hrs. Pulled tstats and lower unit, rigged a cheap bilge pump to the pickup tube with a piece of garden hose. Put the pump in a 5gal bucket of rydlme solution setting the pump on a brick a few inches higher in the bottom of the bucket, hooked it to a battery and circulated that solution for about 4hrs. I got an inch of solids in the bottom of the bucket when it was done!! Inside the thermostat holes it went from crusty to clean! So I assume inside the block did the same. Use Salt Away every flush since
AlwAys like seeing you use snap on tools - 1/4 inch swivel socket on poppet valves. When I retired- I kept all my snap on hand tools.
Right on
First thing i do when i get a motor is get a manual. Learn how it works and how to take care of it. like high grade filters and de-scaleing . keep any problems from happening.
Had an old Nissan 70hp that would only over heat at WOT for a min or 2. Turned out being some buildup in the heads. Had em pulled and cleaned and ran great ever since
Another great video. Would love to see one on how to service/clean Yamaha ISC valves. Not much info out there on these imo.
I dont think those have much coverage either, but there's not really enough substance there for a vidoe :/
Hello
My marine superchager 300 engine it’s displayed on acreen supercharger over heated. I did change the sensor and still over heated on high speed only
Looking for your advice
Thank you
I had an I/O overheat from Ice in the water pipe coming out of the leg on a 60* January day. It resolved after a few minutes sitting in the water melted the Ice.
As always, your videos are second to none - they are more like tutorials. I remember back in the day when i didn't know anything about boating, I had a 2000 Mercury 150 which would overheat at low RPMs. Clearing any channel was a stressful experience because the alarm would go off.. After researching i learned the poppet valve could have been the culprit so i changed it and that fixed my issue.
Glad to help!
Am having similar issues on my twin 300 Verados but mine is when I am
Idling as soon as I rev up the RPMs goes from 200 to 160
@@malex1403 , a mechanic told me to replace the poppet valve and that did the trick for me. I hope this helps!
You forgot the water tube grommet that connects at the bottom of the power head dislodging.
I had a mercury 7.5 that was my first motor. I bought it and was so stupid but did not see if it was pissing water. So I took it out and it overheated, brought it home and changed the impeller, nothing. It didn’t have a thermostat so I didn’t have to worry about that. I asked around and came to the conclusion there was a blocked passage way so I blew air through and nothing. I took the engine block off and turns out a little o ring like thing was melted and clogging the water passage. I checked every marine store around and found one that had been on the shelf for over 20 years 😂
Eman Kosak whenever I’m working on some old or obsolete machine or equipment I always think that to myself. Somewhere in this world there’s a part for this in a dusty warehouse sitting on a shelf for twenty something years. Now am I able to find it? 🤔
Fireship1 haha very true.
Great info! Thank you. I’m not sure if my 1990 Johnson 70 2 stoke has a poppet valve. Anyone know if it does? I haven’t seen anything like it after multiple hours of working on her.
Not sure, I just looked at boats.net and didn't see one. (I just did a quick scan) it might not, a lot of the small engines don't have them because they don't need them. A 70's right there in the middle, it's not really a small engine, but it's not a big engine :) Those 50-115's are all mid-range engines like that.
Yes it should be like this one epc.brp.com/Index.aspx?lang=E&s1=25d5e0b4-1d47-4c2d-9a21-cdca06192200 The vernatherm (thermostat) is in a plastic housing which incorporates a an external Spring thus acting as a relief/poppet valve. A lot of the Johnson/Evinrude Poppet valves are actually set up like this.
2011 F25 overheat alarm came on .. boat slowed down … engine was pissing but was hot . Not normal … luckily made it back to land moving real slow and turned engine off . Could this be a thermostat issue as it was in idle in shallow water before the boat left land . No debris found in the foot
Could have been you picked something up, hope you figured it out
I brought a 14ft 79 fleetline sapphire mk4 with a 85hp Mercury Blueband. I've just done a compression test and found all 4 cylinders running under 100psi the impeller housing melted with 3 missing fins I'm a full novice that is going to attempt to strip and rebuild
Hi question for you the 200 Yamaha saltwater series has that poppet valve? I’m talking about two stroke engine?
Yes, as I recall it is located under the CPU. Several sites have expanded/exploded diagrams which will show the location.
richard thomas hi Richard if you can make a video showing were is the poppet valve in the 200 Yamaha two stroke I really appreciate thanks 👍
J Glez sorry I can’t video the item however a quick search of UA-cam specific for “poppit” should turn up several sources like ua-cam.com/video/SQdFHiMgkKM/v-deo.html
richard thomas thanks 🙏 now I know thank you again
any tips or tricks on trying to clean out corrosion? hear of some guys putting diluted vinegar in a drum and running the engines for while
Is it good practice to FRESHWATER RINSE Outboard motors used in the ocean...????
Thank you
Yes it is especially if the engine is going to sit for aa while before it used again. I recommend running the engine for a least five minutes on a flusher.
Yes, it's a good practice to have :)
I have a 150 hp mercury the engine works very well in fact last weekend we sailed 100 miles and had no problem, but when I leave it on low the engine temperature increases to about 200 gf, the engine was 10 years without use, for It's pretty clogged inside. Can you recommend a good chemical to wash the inside of the engine? thank you so much
Have a 92 v6 Yamaha that would overheat above 4000 rpms. Pulled the heads to find most passages completely clogged. Cleaned em all out and havent had an overheat since.
Hello,
I have a suzuki df60A, and can't remove the valve of the water pressure, it's kind of stuck. Any idea about how to operate?
Hey big fan of the content. I recently made a big mistake. I flushed my engine with a hose that was loaded with sand on my 05 yahama 115. I was able to unclog the pee hole but now there isn't really any water getting down to the lower unit out the screens. Looking for suggestions to flush the sand out in the system. Thanks!
Try dropping the lower unit and flushing it on the flush hose
@@BornAgainBoating thanks for the reply. I'm doing it now
I have a2014 Yamaha 40hp four stroke cylinder and I have replaced both thermostat and impeller the replaced the thermostat thinking it was bad because I thought it wasn’t letting water to run through it and when took off and ran the engine water came out so that means the impeller is working I took off the tattletale hose and cleaned it out there was nothing inside the hose and it was dry need help where else could I look
This is perfect timing! I was coming back to the dock from a day of fishing on Sunday and at idle I started getting an overheat condition so I turned off the motor and I had to keep putting around in order for the engine to stay cool but every time I sat at idle it kept overheating. Last time that happened to it was the waterpump impeller but this one only has less than 60 hours on it. Could it be a thermostat? Thanks! 2013 Yamaha F150
Yes. It could be the thermostat, but you're right, that sounds like an impeller issue :/ pull the stat and see what it looks like!
I pulled it and it still looks good! No sand or gunk on it. A little bit of green corrosion checked the temp specs in a boiling pot. How often do you recommend changing thermostats? This one has about 500 hours on it
Poppet valve?
Once again you guys have taught me a thing or two when I thought I had it down. Specifically the number of items in an outboard that can be water cooled. I knew about superchargers but nothing else. I've always gone by the notion that as long as the outboard is vertical all water will drain. This is very important for boater's in northern climates but maybe it doesn't always hold true? Do some outboard's have drain plugs that need opening for winterizing to ensure all water is out?
Thank you! And not that I know of, once you trim them down the water drains out
Thanks man! Followup question....do you know if my 2004 Yamaha 90 4-stroke has one of those poppet valves?
@@BornAgainBoating where is the poppet valve in a 2008 50hp 2 stroke mercury outboard 3 cylinders thank you 😊 God bless
mercruiser 470 overheated bc of an airlock in the coolant system after a full drain bc i had to install a new starter. a vid about how to install an i/o engine temp alarm would be greatly appreciated. thanks for the vids
Hi guys, I just bought a 1982 Johnson 150hp v6. They said it ran fine, but when I pulled the thermostat housing I noticed that it didn't have any, also they had two different springs for the pop it valves. I also found that the top carburetor didn't have the retaining clip to hold the needle to the float. So the top needle looked brand new while the other two showed signs of wear. Checked compression and it was low and all over the show. Heads were a little warped, just had them skimmed. So I definitely reckon that it had majorly over heated. Do you have any other thoughts on why they soul have or why they had to do this. Cheers and thank you for channel, love your content. Sav, Australia.
Thats really hard to say, it sounds like there were multiple problems and multiple people trying to fix the problems and in their own way :/
Cheers, I'll wait and see when the new gaskets arrive. Hopefully it's going to be a good motor. Was planning on fitting it to my 1982 15ft half cabin cruiser. I have completely rebuilt this boat. From adding more glass to the whole hull, new stringers, new bigger and stronger transom and floor. She should be bullet proof. Love your work keep it up. Cheers from the land down under.
Side note, early Volvo and OMC drives do not have an impeller in the leg. They have a water pump like an inboard.
I have a 2015 Yamaha 150 that has intermitent overheating only when out of the water while flushing, with muffs or a large trash can of water. Just had the impleller relaced, and thermostat looked at by my service guy. Took the boat out last weekend, ran fine and cooled fine with good telltail. Got home and was flushing and no telltale, and began to over heat. With muffs and in the trash can with water. Couple of weeks ago, I did get in shallow water with sand, over heated, service guy pulled pump apart and found impeller in pieces. Was replaced and ran great, but for some reason when flushing I get no cooling our tell tale. Thermostat area seems fine, no sand, but a small amount of corrosion. I'm going to pull thermostat off again today to see if I get flow there. Could there be some sort of other blockage?? Frustrating! Any ideas?
It's not uncommon, it's the backpressure and water issue. You just don't have enough hose pressure and even being in a trash can, sometimes it's not enough pressure. A lot of outboards will have trouble running on hose and can overheat after a couple of minutes of running. You might be chasing a rabbit that doesn't exist :/ are you just totally against flushing from the flush attachment without running the engine?
What's the best way to flush out the cooling passages when there is sand/mud packed in?
Saltaway and good water pressure, but you'll want to pull the thermostats and anodes to let the water push the stuff out. Otherwise you have to pull the heads and other components to clean them out manually.
@@BornAgainBoating thanks! If there are multiple thermostats, does it help to remove one at a time in order to provide better pressure to one half of the cooling system while flushing?
Overheating is the death of more motors then anything I know of. New impeller every few years is worth every penny
I am fan of Salt-a-way / Salt Terminator. I religiously flushed a ski with those products and after several years and 450+ hours later, the water jackets in the manifold looked brand new 👍🏻
Have you had success with using a descaling product on neglected motors?
Salt away is a great product! But on the neglected engines, if it gets to the point where it comes to us, we take them apart and physically clean them, but a lot of the times it was neglected until it blew up! So, I don't have a lot of experience with many descaling products lol :/
My 1998 Yamaha 150 2 stroke is acting like its overheating. It runs fine for a few minutes under load then goes into reduced RMP mode. I've cleaned the water channels, replaced the impeller, replaced the thermostats, replaced the cylinder and water jacket gaskets, and replaced both thermo sensors. I'm going to take the poppet valve off tomorrow and examine it. I shot the cylinders with a temp gun. The left side is running at 150 F and the right at 200 F at idle with the muffs on. Don't know if that's normal or not.
2020 Seven Marine 527 Duoprop outboard is ( closed loop ) cooled. I’d love to see how they pulled that off and how well does it work?
Its a GM LS based engine, there is a heat exchanger (water radiator) fed raw water by a pump. Unless you mean actually seeing how they did it :)
I always forget about them lol I think a $100K outboard is just out of my league :(
@@BornAgainBoating uh yeah that's a big 10-4! I can barely keep my old outboards running let alone paying 100k just for one engine! 😳
Do you do anything with a 1999 250 hp Johnson
😱😱 oh man seeing those saltwater used t-stats and cooling passages feels like a horror movie to me, who runs freshwater a couple of weekends a year lol😆
Always learning something new from you thanks man
Glad to help
I have 2 Yamaha 250 hp 4 stroke engines on my boat
Recently, we had water shortage in the marina where my boat is, and flushing was erratic for about a month.
I noticed that the temp of engines started to show erratic readings, instead of being in the middle range as it was always, it started going up and down but no overheating.
I asked the technician I deal with to take the boat out, change all 4 thermostat and both engines' puppet valves along with overdue replacement of the engines' anodes.
Your video is really educational for those who know or don't know about the tech. stuff about outboards.
Big Thanks
have you ever seen boat owners using a product such as Salt away and noticed any difference with less salt buildup? thanks Aaron great video sir! I've got 1 Mercruiser closed loop, and 3 outboards my 470 Mercruiser needs water circulation pump replaced :( :( switching to all outboards sooner than later haha!!
Yes, salt away does keep the cooling passages cleaner. But you only need to do it a couple times a year depending on how you use your boat :) thank you and outboards are definitely easier to mess with lol :)
Great video! I have a question, what's your opinion on acid flushing the outboard such as rydlyme?
Thats the very last resort, its hard on the engine and I'm really not the biggest fan of doing it
@@BornAgainBoating my outboard is over heating strangely the pee stream runs hot then cold then hot and back to cold each time the heat comes back around it gets voter than the time before till it all just steam?any ideas
Could you make a video to help maintain the cooling system
Basically just service the impellers, thermostats, and anodes. Fresh water flush, and maybe use saltaway once or twice a year :)
can you please tell me what temperature the water coming out the tattle tell of a four stroke 15hp yamaha 2005to2008ish should be?
Not sure, depends on the water temperature you start with. Maybe 130-150, thats just a guess though
@@BornAgainBoating ok thank you.
water is coming out hot enough i cant leave hand under tattle tell. it burns.
I'm not a boater but interesting engineering interests me and outboard motors are very interesting. Check out the videos of Malcolm Oastler. He put a two-stroke Merc V6 in a motorcycle. He modified the poppet valve cover to be the coolant inlet from the radiator. There is an oddly shaped passage to the right of the exhaust passages (the engine is mounted horizontally with the cylinders down) that is the hot coolant outlet to the radiator. He claimed that the water cooled divider plate in the exhaust cavity is now uncooled. I will never have the resources to have a two-stroke V6 put into an old, lightweight vehicle but Mal's videos are lacking in clearly explaining some of his decisions and I'd like to have a better understanding of those decisions. So... If an expert on the Mercury design would wade through Mal's playlistless videos to find the ones that address the cooling system and critique Mal's decisions that would be greatly appreciated.
Do all outboard have poppet valve(pcv)?
No, small engines usually don't. Every brand is different, but for the most part, once you get above say 90 HP almost all do, but then like 70's and below, some do and some don't. The small engine has a small block and head, doesn't take much water to fill them up so the valve isn't needed :)
I have a 06 evinrude 250 that is melting the exhaust pipe and water pump housing I replaced thermostat and followed the wather and not clogs found any ideas?
I’ve always wondered, why can’t they make an impeller out of a composite or brass instead of rubber that fails snd needs to be replaced?
Who knows!
two reasons why impellers are made of rubber not brass.
1. if solid debris such as mud get into the pump, rubber impeller will pass it through while brass impellers will not and would cause the impeller to jam up.
2. The pump housing is not quite circular in shape, thus the rubber impeller.
That is my humble opinion :)
@@nayefalhajri7927 the "center" of the water pump is off center, causing the fins to compress on one side and expand on the other, thereby creating the pressure to pump the water. Rubber flexes to create that offset pressure..
Passages around cylinders and out the block closed loop had tell tale
Awesome stuff! Thank you for sharing 👍
You bet!
I have water in the oil. It’s a real white milky sludge in my DF225 Suzuki . Is this due to over heating?
Ouch! Probably not because of over heating, but because of a blown gasket somewhere. You'll need to figure out where the water is coming from before doing anything else. You don't want to cause more damage to the engine by running it like that and letting it blow up!
Great video . I’m running a 2 stroke 1990 Evinrude 60. I’m currently trying to trouble shoot if it is fuel issue or overheating. My boat will start up and run fine for a good little while. After stopping to fish for awhile , it refuses to fire back up. I crank and crank with no turn over. Wondering if anyone else has dealt with this? Going to change the impeller regardless since I just got the boat. Any help would be appreciated.
Could be overheating, but make sure its not loosing fuel by an air leak in the system, try priming the bulb after you stop and see if it gets fuel and starts
Check spark. Coils under flywheel may be going
Bought a boat with a 1984 115 hp evinrude overheating Pulled the pump and it was clogged 75% with sealant some the guy getting crazy with it stuck one of the plastic by pass with spring things that goes to one side of the motor crazy
Here's a question. 2007 yam 250s. Why does one engine have bubbles coming out of prop and other doesn't. Both were scoped and actually are perfect
I've got a 70hp Johnson ,it runs on foot but in lake it bogs and won't hardly run??
very useful video.
Thanks and greetings from Bulgaria
You are welcome!
Yamaha 60tlrz. Will throw overheat alarm after idling for a while or idling after running wot. Changed temp sensor, thermostat, impeller, then rebuilt whole water pump with new impeller, tested thermostat and temp sensor on stove with hot water, pulled head and exhaust cover to check for blockages. Everything clean. 98% sure this model does not have a poppet valve. I just can't build enough water pressure to keep it cool at idle. Very annoying.
I just rebuilt a Yamaha F100TLRA which had spun a rod bearing, and on initial break in test (with the water hose fitted, not on the water) I also had an issue with overheat alarm coming on when idling for a few mins! with the engine running at half throttle continuously for 20min, no alarm. reduced throttle to 10% but still in gear, alarm also came on after a few min. if alarm was on, it would not turn off if accelerated, but I only tested that for a few seconds so as not to damage the engine. it was shut off each time and on restart, no more alarm. if idling, would alarm within a few mins. I found that the tell tail restrictor is missing, and my assumption is that the cooling system on this engine will overheat without the tell tale restriction at idle due to lack of coolant jacket pressure. I think that the impeller can't generate enough psi without the restrictor and the water around the cylinders starts to boil or otherwise slowly drain out of the jacket leaving the engine to overheat when idling. I will test various scenarios with a restrictor in place.
I have over heat engine and not water coming out port turn out was impeler get to the marina after boat us tow my boat take lower unit off and replaced and 1/2 hour later back in the whater finish up the good day fishing
Sevens marine outboard has closed loop cooling
I have a 200 mercury with a new water pump new thermostat and its still over heating when throttled up should i replace the poppet valve i am a loss .
You can try, you might have something else going on, water tube, water pump housing problem, etc
I have a 2008 chaparral 204 ssi and is overheating but I check the outboard and I don’t find the tell-tale?
HOT TIP; I Started and Ran a 175 hp merc outboard on a trailer and without water!
3 seconds and shut it down.
Water Cooler Impeller ; disintegrated.
Define; weekend shot?
Haha yeah I heard they go very quickly but not THAT quickly :D
@@eamh2002 famous last words bro; without any exaggeration.
Nylon??? Perhaps titanium would be best?
Turned my $12000.00 merc out board into a very noisy marshmellow roaster.
Tuesday? Time to give that thumbs up!
Sir what is called for the water coming out of the engine🤨🤨🤨
What is the disadvantages of running without thermostat?
Check out this article, has a lot of the details there :) www.bornagainboating.com/outboards-without-thermostats/
Did you see the salt and sand buildup in some of those outboards. Oh my
I have an older Johnson 120 vro that is making this beeping sound from time to time. The constant beep is coming from the console. Any ideas on what it may be?
I have a 1958 mercury 35 hp and it is getting water into cylinder causing it to foul the plug. Any help please ?
Probably needs a head gasket