These are by far the best instructional videos out there today for boat owners wanting to maintain their own equipment. Thanks for making them and I really appreciate the no-nonsense approach you demonstrate. Take care and keep up the great work.
3 years down the road and your still saving the day.. From the Amite River in Louisiana, Thank you so much.. your videos have played a big role in maintaining my presence on these waters. You are the man!!
This is the ONLY video or the only time PERIOD that I have heard anyone mention that cylinder compression can blow OUT through the water jacket. I have an old Gale that has grey sludge in the leg and in the impeller housing. It pumps water at idle but not when throttled up. Compression is forcing water THE OTHER WAY as the engine is throttled up...problem....bad head gasket between water jacket and cylinder blowing mixed gas from the cylinder down through the water tube stopping the water flow when compression is high and thus....GREY SLUDGE....oil, gas and water mixture in the leg and impeller housing. I am changing my opinion of this fellow......GREAT vid.
Wow brilliant. Thanks dangar. This is the best outboard channel imo. I think your information here has solved my 8 horse yamaha problems. Compression was 145. Sporadic tell tail . Bought a laser thermometer. 120 c . My other identical motor runs at 45c Cleaned all the passages. And found that the rubber gasket on thevwater pump can get pushed in from the connection tube from the upper leg .impeller bits were found in the lower part of the impeller underneath the stainless steel cup that the impeller seats in as well as a small side chamber at the side of the cup. I put a rag on the drive splin and a drill a rotated clocknwise while the lower leg was immersed in water It did pump water
Thanks heaps, just looked at a motor today which had no tell tale water, and abandoned the boat because I couldn't do a water test (no arguments from the seller). Several hours research later and being a lot wiser (thanks to your video among others) I realise I could potentially have fixed the issue, had a water test, and bought a boat. Wished I lived near you, I'd spent some time working for you for free LOL, just to learn.
I had no idea that the tell tale only indicates that the pump is pumping. I thought it meant the engine was being cooled. Thanks for pointing that out Stu. I learned something new today.
Hey mate. It does depend on what engine you have. The tell tale on my 1993 mercury black max 175hp is tee'd off after the thermostats so will only show water if the water is running through the heads and the thermostats are open.
And then you have my 50HP Johnson - no tell tale at all! That worries the missus no end as she thinks there is some thing is wrong with the engine because everyone else's engine has a tell tale. The following year model had a tell tale low in the exhaust cover. A few years later they went to the top of the block - supposedly to vent air out of the water jacket at start up and so prevent an air bubble forming. The tell tale on the Johnsons eventually ended up in about the same place as the one in the video- I don't know why. I do know that tell tales after the thermostat was done on only some engines and the tell tales before the thermostat were done soon after- why? Too many warranty claims/work because people were bringing their engines back in because the tell tale was not flowing when doing a flush and/or when the engine was first started up. People would panic, cancel their day on the water and not want the engine back until the water was flowing as soon as the engine ran.That hole to the cylinder top from the water jacket does not make sense. Could it be a decompression valve hole?
I would say by far the majority of motors have a tell tale straight away but checking the owners manual for your exact model is definitely the way to go to be sure!
Dangar Marine thats true bud! On my 50 merc there is a huge problem of having no tell tale because there is 2 different plastic elbow fittings that clog easily. The tell tale hose runs from the bottom of the block. So I learned how to correct it on a Louisiana merc refuge forum. There is a brass hex plug on the top cyl that is the same size as the plastic elbow on the bottom. Remove brass plug and put it where the bottom elbow is. Put the plastic elbow (or i bought a new brass one) on the top. I drilled out the pisser exit hole and ran 5/16 line straight down to the exit. No more bends.Now i have a TRUE indication of water cooling because its after the thermostat. Now my motor never has a blockage and always pees. I even called Mercury because i was worried that there was a reason like back pressue, for the design. Mercury told me I was totally fine and you can even use a larger hose because its has no effect. The next best thing to do is run a temp and water pressure gauge. What everybody down here does is change the tell tale and add a temp gauge and as Danny on the refuge says "No more looking back when driving the boat". Im thankful the guys showed me this.
I'm attempting to strip down and rebuild a 85hp Mercury Blueband as a complete novice from watching your vids. So far I've run a compression test with all 4 cylinders running under 100psi I've found that the impeller is completely munted with 3 missing fins and the housing has melted..I believe that 2 fins have made it up to the head somewhere. Thankyou for making awesome vids👍🏼👍🏼
I can always count on finding helpful information when I watch your videos :) thank you. I had something strange happen today and would like to know if you have heard of such a thing... 2007 Yamaha 50hp 2 stroke. Haven't been out on the water in a few months so today I was cleaning up the boat and decided to run the motor. Hooked up the muffs, turned the hose on full blast, went to start the motor, got a couple revolutions out of it and it stopped. Switched to both batteries on, still no turning. Checked voltage and had 12.6v. At that point I pulled the plugs and the bottom cylinder had water in it. Kinda brownish/dirty. Cranked the motor for 20 seconds or so and shot all the water out. Cleaned off the plugs, put them back in, and she fired right up. Ran it for 30 minutes on the hose, everything seems normal, revved up a couple times, so far so good. Pulled the bottom plug again and didn't see any water in there, kept the hose running and still no water that I could see getting into the cylinder. Any idea how that water could have gotten in there? What should I look into next? Or just run it and see how she acts on the water before getting any deeper into it?
Thank you very much for this video. My outboard spat air through the telltale and overheated, and I found that the top gasket was blown after watching this.
Awesome explanation. I was taught (incorrectly) many years ago that the tell tale was the "last" of the water and that if it was coming out then it was flowing everywhere correctly.. I was also taught to wait until the tell tale water was warm as that indicated the engine was warm enough to start opening up the engine.. Geeez Grandpa.. You had me fooled all these years :P
That depends on the engine. Some Johnsons had the tell tale plumbed up to outlet side of the thermostat in the 1975 - 1980 time frame.But the wait until the tell tale water is warm is not a bad idea. As you can see from the video, the cold water side will still get warm before the thermostat opens up , and then stay warm because the thermostat will control the temps and keep it that way. But that tell tale should never be hot. So letting the tell tale get to be warm before opening up the engine full throttle is not a silly idea at all.
Okay, I bought a boat without the motor running. I figured how hard could it be. Well, no spark in one plug and low compression in one cylinder 60psi. After trouble shooting I ordered a new power pack as I feel that is the issue after testing and moving wires around. Next for the cylinder I am going to try the Marvel Mystery Oil to see if it loosens up the rings. It's such a crap shoot for us backyard mechanics - so to speak. I know I may have to replace the head gasket but first things first so I am just waiting for the power pack to arrive. Your videos have been extremely helpful as this is the third boat I have worked on after watching the videos. Keep them coming! P.S. If you were in Canada even Ontario or even Hamilton I would be knocking your door down for help. LOL
Great video! This has helped me confirm that the headgasket is blown on the 55hp vintage Chrysler (Sea King) that I have been repairing. I finally got it running well yesterday but I noticed that water just blasts out of the telltale (with steam too) so I think I will have to get that headgasket replaced. The thermostat is probably stuck as well since water only came out of the telltale (bottom end is off so I can see what comes out). Thank you!
Yes, the steam and shooting water is definitely a fair sign of a blown headgasket. Good luck getting it fixed up, sounds like it will be fine once the job is done.
Your videos are so informative and educational Thank You!!! I have been working on my 1986 Mariner and have managed to rebuild the starter and am currently looking at rebuilding the carburetors. Luckily this outboard has only been in freshwater and has minimal corrosion.
Greetings from tampa Florida Master Stu big proud happy followers of yours here . I have a 96 Johnson 225 and I’m having overheating problems I suspect sand on the heads , gotta go easy on the islands this summer i supposed , Cheers 🍻 my friend .
Hi mate. Yes, sand can certainly block up a cooling system fast. You can try taking off the gearbox and the thermostat cover to flush it out backwards with a hose.
Great learning video for me. I actually assumed a strong tell tale flow of water meant an engine has to be cooling. Good to know it may not be. Thanks stu.
hi stu from all in Manchester England and thanks once again stu now thats the vid i have been waiting for your videos are an inspiration to all keep up the good work
what was it doing ? my johnson has a weak tell tale and nothing out the exhaust hole , I am going to check the thermostat and pull the leg , it should have a new impeller
GREAT VID. I live in one of the worst water conditions to run any boat in but just so happens that it's the best place to boat. S.W. Florida in the USA we have dirt, mud, and shells shallow water every where and a mix of fresh and salt water. In the past with older outboards I've used muradic acid to get rid of The Saltwater scale that formed inside the engine this is tricky because you cannot let it set for very long and it will do internal damage. but it did work very well to keep the engine running cool. When you get to the point where there's nothing to lose there's, nothing to lose. I have a suggestion is to dip one of those engine parts in muriatic acid and show your viewers just how fast it would work. Best Regards, and boating
Hi Tim. Yes, I'm planning to do a video comparing various cleaning agents soon. I might do it this week actually while it is topical. I'm thinking Muriatic (hydrochloric) acid, vinegar and Salt-Away. It will be interesting to see!
That’s why my 25hp outboard was hot on idle but pumping hot water. The water jacket was blocked. Outboard had been sitting for a while, by running in the ocean it cleared the blockage and water shot out the upper exhaust port. Thanks
Exactly the information I need! My 25hp yam has that exact engine block. Tell tail pumping very strong but I noticed the spark plugs turned blue. Thermostat was packed with sand. Suspect that is not the only issue since the previous owner melted the impeller and its housing. Hoping to find an obvious peace of plastic blocking a port. Thank you! 🇮🇪
Good info. No problems for me now but good to know what symptoms of future problems might mean for trouble shooting. Especially if buying a used motor. Thumbs up!
Great vid - thanks Stu! As regards the purpose of the second smaller exhaust port - possibly to improve scavenging in the cylinder? I dunno. Anyway - cheers 🍻
You need to get paint pen to mark the year and then make and hp and on the lower unit how long it is. On the motor you have laying around plus when you work on somebody's motor are working on your own motor you can write the date on it. So that whatever part of the motor you are working on. You and who ever the motor belongs to will no when it was replaced or when it was rebuilt or if you just service the motor. This is what I'm going to do so that I know. Im a first time boat owner I really like your videos . It's giving me helpful hints of what to check and look for on the used pontoon boat I just bought that has a 1990 60 horsepower Johnson pro series with three cylinder that hasn't been ran in over 6 years.
I know this is a decent thread dig but the extra exhaust port holes are bleed down ports to reduce cranking compression for easy starting. In some cases, they are just small extensions to the top of the exhaust ports.
Perfect explanation. I was getting a poor tell-tale flow so went to the impeller. 2 blades snapped off and only 1 still in the pump housing - so how to find the lost one? Didn't understand the Yamaha cooling system as the service manual doesn't cover it. I didn't know where to begin. Based on your info I think it's likely sitting where the vertical water pipe meets the block. I'll drop the lower unit again and try running water through the flushing port to see if I can flush it out. Really excellent explanations - thanks man!
Interesting to watch your clock now that you have done a tutorial on battery changing, and see how long it takes to put a video together, all you need now is a digital date movement so we can see how much time goes into doing the job.
I never really thought about it being good for that. This one actually went pretty quickly from memory as I was rushing to get somewhere else, but some take much, much longer than the 10-20 minutes they end up being.
Very instructional, Stu - as usual. Armed with this I'm going to go back at my little Johnson 3.5 hp water flow issue. No water out the telltale however water is being spat back out the four little pinhole exhaust ports halfway down the leg. Somehow water must be getting pumped up to the head and although blocked in the telltale channel somehow, it is still making the journey around the jackets and back down and out. After seeing your vid I see how this might be possible.
Good morning Stu, Excellent video as usual, not something I need to do at this time and I'm happy about that : ) In one of your previous videos on voltage drop and Ohm's law, you used hydrochloric acid to clean some of the corrosion off some wires, so I went in search for some at my local hardware store but they didn't have any then went to several other stores still no luck but what all of them did have was muriatic acid so when I got home I googled muriatic acid and found out that muriatic acid has another name ( hydrochloric acid ), After running my face straight in the wall, I went back to the hardware store and bought a one litre bottle of muriatic acid and it worked like a charm, I'm guessing I failed chemistry in school LOL
Great video !!!! Funny I have a mercury 2 stroke 225 EFI and my issue is the engine is not warming up (all heads are at 90 deg).... Changed stats, checked compression, checked water pressure... And still same issue...
Wish I had seen this vid before I started trouble shooting my failed tel tail pisser. Removing the exhaust cover seemed an easier place to start than dropping the lower end for the impellers. Now I need a vid on removing snapped bolts....
Your videos are great, keep them coming. I actually have an 50hp Johnson with bad idle and something causing some water to get on lower cylinder. Watching your video of headgasket replacement and this (even they are from yamaha) gave me some pointers what to expect when i start to tear it apart. :) There are not so many good outboard repair videos on the youtube at the moment.. Actually most of them are really dissapointing to watch. :D
Most two stroke head gaskets are pretty similar, and fortunately pretty each to do. Just take a good look for any damage to the block and head before you put it back together.
you do good stuff and explain things well. do outboards routinely do overheat alarms? with modern electronics it would not be too difficult to knock up a simple one for a few dollars.
Hi Norman, yes, they have a thermo switch that is linked to an audible alarm and they will usually go into a limp mode to cut maximum RPM but allow you to get back to the boat ramp.
Just got my Johnson 90 serviced here in Dubai. Because of the high temperature here, they told me to remove the thermostat which always are open anyhow to help the flow of water.
I presume they must have a fair bit of experience with your local climate. Things leave the factory the same whether they are going to Greenland or Dubai!
Looks like I'll be replacing my thermostat now......as a preventative measure. I has assumed a good flow out of the tube was all I was looking for. Thanks for potentially saving my engine.
Thanks for your reply on another of your videos.... the very last section re: new thermostat..new heat sensor, new impeller, good flow up to thermostat.... pleaseeee dont be the head gasket!!!!
The port that is connected to the exhaust is autocompretion. It is working only when you start the engine. In the first stroke, when the engine start to crank, it release the comprention then the electrical engine will run early and faster.
Thank you because now I have a clue as to what's going on in my coolIng system. You explain everything so that anyone can grasp the content. Looks like the cooling systems gets a lot of mineral build up over time. Is there a way to flush vinegar or something to take out the mineral (crusty) build up to prevent Clogs?
I think the small exhaust port in the cylinder may be an E.G.R. Port due to the location of the port. Kindly makes sense cause there’s water flowing around those ports on the cover plate. Don’t know for sure though.
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 tale 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.
If water is flowing up to the thermostat and the thermostat is opening it can really only be blocked cooling passages or a blown head gasket (which allows the combustion gasses to blow the cooling water out of the jackets)
@@DangarMarine Thank you so much for your feedback. Will relay this information to my mechanic. Yes water is flowing up to the thermostat, yet i have noticed that the top 2 cylinder heads (ones closest to termostat) are the ones which are heating up the quickest. The bottom 2 feel relatively cooler. He is coming over on saturday and he wants to remove the engine block and check for water blockages in the water passages under the engine block. Does this make any sense to you ?
@@DangarMarine may i please ask you what you mean by "if the mixture is lean" what mixture are you referring to please? Also the tell tale water flow is constant, you mentioned in your video that an inconsistant water flow may mean that combustion gases are mixing with water.
Always watch your videos really good work and thanks for taking the time to educate boat owners. Need you to point me in the right direction 2007 optimax. Water on cylinder #2 replace water jacket and o rings still a couple off drops in cylinder good compression where to look next thanks in advance👍
Hello Dangar Stu! I'm a big fan of your channel. This video is very informative, thanks. I have a small amount of water coming into my cyclidars, mainly the top one. The head cover gasket is old but looks intact. Same with the side water gallery plate. No apparent cracks in the block. Water leaks in weather the engine runs in the water or with muffs. Where else could water leak in? My engine is a 1990 johnson 40hp 2 stroke. Would love to hear your take on this. Thanks. Keep up the good work!!
Another excellent tutorial. I have a 90 Yamaha 2 stroke. 20 years old and runs great. Just started getting hot after 10-15 minuets of full throttle. The Alarm sounds. It was fine at idle or low speed. Turned out to be popitt valve by thermostat. It was clogged with salt deposits. My question is... do you think it’s worth taking the head off just to inspect the water jackets? If corroded of clogged How to clean? What to clean with? As I said it runs excellent after cleaning popit valve. But im guessing there could be crud in there if the popitt valve had deposits. Thanks for your excellent videos and easy to understand tutorials
This video covers a few choices for cleaning the outboard. If it is running well now I would just try flushing a few times before taking the head off. The trouble with removing the head is that as well as needing a new head gasket, you don't know what else is going to happen with regards to bolts breaking etc. It needs to be really worth the risk. Here is a vid on various cleaning options ua-cam.com/video/8w_o5xB8ZFI/v-deo.html
These are by far the best instructional videos out there today for boat owners wanting to maintain their own equipment. Thanks for making them and I really appreciate the no-nonsense approach you demonstrate. Take care and keep up the great work.
BTW, Is that Marvin the Martian on the bow/foredeck? Little green man for the Green Machine.
It is! My step son and I painted it on one day.
3 years down the road and your still saving the day.. From the Amite River in Louisiana, Thank you so much.. your videos have played a big role in maintaining my presence on these waters. You are the man!!
Pozz.
Trebam savjet. Ako se možemo čut privatno.
Tnx
This is the ONLY video or the only time PERIOD that I have heard anyone mention that cylinder compression can blow OUT through the water jacket. I have an old Gale that has grey sludge in the leg and in the impeller housing. It pumps water at idle but not when throttled up. Compression is forcing water THE OTHER WAY as the engine is throttled up...problem....bad head gasket between water jacket and cylinder blowing mixed gas from the cylinder down through the water tube stopping the water flow when compression is high and thus....GREY SLUDGE....oil, gas and water mixture in the leg and impeller housing. I am changing my opinion of this fellow......GREAT vid.
Wow brilliant. Thanks dangar. This is the best outboard channel imo. I think your information here has solved my 8 horse yamaha problems. Compression was 145. Sporadic tell tail . Bought a laser thermometer. 120 c . My other identical motor runs at 45c
Cleaned all the passages. And found that the rubber gasket on thevwater pump can get pushed in from the connection tube from the upper leg .impeller bits were found in the lower part of the impeller underneath the stainless steel cup that the impeller seats in as well as a small side chamber at the side of the cup. I put a rag on the drive splin and a drill a rotated clocknwise while the lower leg was immersed in water
It did pump water
Thanks heaps, just looked at a motor today which had no tell tale water, and abandoned the boat because I couldn't do a water test (no arguments from the seller). Several hours research later and being a lot wiser (thanks to your video among others) I realise I could potentially have fixed the issue, had a water test, and bought a boat.
Wished I lived near you, I'd spent some time working for you for free LOL, just to learn.
Your welcome Keith, probably better not to buy a good boat than buy a bad one. Caution is often a good thing.
I had no idea that the tell tale only indicates that the pump is pumping. I thought it meant the engine was being cooled. Thanks for pointing that out Stu. I learned something new today.
Hey mate. It does depend on what engine you have. The tell tale on my 1993 mercury black max 175hp is tee'd off after the thermostats so will only show water if the water is running through the heads and the thermostats are open.
And then you have my 50HP Johnson - no tell tale at all! That worries the missus no end as she thinks there is some thing is wrong with the engine because everyone else's engine has a tell tale. The following year model had a tell tale low in the exhaust cover. A few years later they went to the top of the block - supposedly to vent air out of the water jacket at start up and so prevent an air bubble forming. The tell tale on the Johnsons eventually ended up in about the same place as the one in the video- I don't know why. I do know that tell tales after the thermostat was done on only some engines and the tell tales before the thermostat were done soon after- why? Too many warranty claims/work because people were bringing their engines back in because the tell tale was not flowing when doing a flush and/or when the engine was first started up. People would panic, cancel their day on the water and not want the engine back until the water was flowing as soon as the engine ran.That hole to the cylinder top from the water jacket does not make sense. Could it be a decompression valve hole?
I would say by far the majority of motors have a tell tale straight away but checking the owners manual for your exact model is definitely the way to go to be sure!
Dangar Marine thats true bud! On my 50 merc there is a huge problem of having no tell tale because there is 2 different plastic elbow fittings that clog easily. The tell tale hose runs from the bottom of the block. So I learned how to correct it on a Louisiana merc refuge forum. There is a brass hex plug on the top cyl that is the same size as the plastic elbow on the bottom. Remove brass plug and put it where the bottom elbow is. Put the plastic elbow (or i bought a new brass one) on the top. I drilled out the pisser exit hole and ran 5/16 line straight down to the exit. No more bends.Now i have a TRUE indication of water cooling because its after the thermostat. Now my motor never has a blockage and always pees. I even called Mercury because i was worried that there was a reason like back pressue, for the design. Mercury told me I was totally fine and you can even use a larger hose because its has no effect. The next best thing to do is run a temp and water pressure gauge. What everybody down here does is change the tell tale and add a temp gauge and as Danny on the refuge says "No more looking back when driving the boat". Im thankful the guys showed me this.
I'm attempting to strip down and rebuild a 85hp Mercury Blueband as a complete novice from watching your vids. So far I've run a compression test with all 4 cylinders running under 100psi I've found that the impeller is completely munted with 3 missing fins and the housing has melted..I believe that 2 fins have made it up to the head somewhere. Thankyou for making awesome vids👍🏼👍🏼
I can always count on finding helpful information when I watch your videos :) thank you. I had something strange happen today and would like to know if you have heard of such a thing... 2007 Yamaha 50hp 2 stroke. Haven't been out on the water in a few months so today I was cleaning up the boat and decided to run the motor. Hooked up the muffs, turned the hose on full blast, went to start the motor, got a couple revolutions out of it and it stopped. Switched to both batteries on, still no turning. Checked voltage and had 12.6v. At that point I pulled the plugs and the bottom cylinder had water in it. Kinda brownish/dirty. Cranked the motor for 20 seconds or so and shot all the water out. Cleaned off the plugs, put them back in, and she fired right up. Ran it for 30 minutes on the hose, everything seems normal, revved up a couple times, so far so good. Pulled the bottom plug again and didn't see any water in there, kept the hose running and still no water that I could see getting into the cylinder. Any idea how that water could have gotten in there? What should I look into next? Or just run it and see how she acts on the water before getting any deeper into it?
Excellent!...As a shade tree auto and marine mechanic I am impressed by your down to earth presentation, diagnosis, prognosis and repair!
Thank you very much for this video. My outboard spat air through the telltale and overheated, and I found that the top gasket was blown after watching this.
Glad it helped
Great work, very informative videos. You can't beat experience picking a blown head gasket.
Thanks for the eye opener Stu.. wow more galleries than a Parisian street...tells a great tale about cool water
You are quite the cunning linguist! ;)
little tongue in cheek eh
Awesome explanation.
I was taught (incorrectly) many years ago that the tell tale was the "last" of the water and that if it was coming out then it was flowing everywhere correctly.. I was also taught to wait until the tell tale water was warm as that indicated the engine was warm enough to start opening up the engine.. Geeez Grandpa.. You had me fooled all these years :P
That depends on the engine. Some Johnsons had the tell tale plumbed up to outlet side of the thermostat in the 1975 - 1980 time frame.But the wait until the tell tale water is warm is not a bad idea. As you can see from the video, the cold water side will still get warm before the thermostat opens up , and then stay warm because the thermostat will control the temps and keep it that way. But that tell tale should never be hot. So letting the tell tale get to be warm before opening up the engine full throttle is not a silly idea at all.
Thanks for the clarification
Thanx Stu, you're the man when it comes to outboards. Love your work and keep'em coming!!
Okay, I bought a boat without the motor running. I figured how hard could it be. Well, no spark in one plug and low compression in one cylinder 60psi. After trouble shooting I ordered a new power pack as I feel that is the issue after testing and moving wires around. Next for the cylinder I am going to try the Marvel Mystery Oil to see if it loosens up the rings. It's such a crap shoot for us backyard mechanics - so to speak. I know I may have to replace the head gasket but first things first so I am just waiting for the power pack to arrive.
Your videos have been extremely helpful as this is the third boat I have worked on after watching the videos. Keep them coming!
P.S. If you were in Canada even Ontario or even Hamilton I would be knocking your door down for help. LOL
Good luck with the fix mate, hope it goes well and glad the vieeos have been helping.
Really appreciate all your videos. Thanks for taking the time to share your experience with us. Cheers!
Thanks Joe, glad you like them!
Great video! This has helped me confirm that the headgasket is blown on the 55hp vintage Chrysler (Sea King) that I have been repairing. I finally got it running well yesterday but I noticed that water just blasts out of the telltale (with steam too) so I think I will have to get that headgasket replaced. The thermostat is probably stuck as well since water only came out of the telltale (bottom end is off so I can see what comes out). Thank you!
Yes, the steam and shooting water is definitely a fair sign of a blown headgasket. Good luck getting it fixed up, sounds like it will be fine once the job is done.
Your videos are so informative and educational Thank You!!! I have been working on my 1986 Mariner and have managed to rebuild the starter and am currently looking at rebuilding the carburetors. Luckily this outboard has only been in freshwater and has minimal corrosion.
You're welcome. Hope the vids are helping you with your rebuild. :)
Thanks Stu. You have given me some clue to my overheating outboard. Much appreciated.
Glad to help
WOW the salt water sure can clog up your system and lessen the cooling of the system. Great video thanks from Canada.
It sure can. These outboard live on the water so they are never flushed, and to be honest, this one wasn't that bad!
Greetings from tampa Florida Master Stu big proud happy followers of yours here . I have a 96 Johnson 225 and I’m having overheating problems I suspect sand on the heads , gotta go easy on the islands this summer i supposed , Cheers 🍻 my friend .
Hi mate. Yes, sand can certainly block up a cooling system fast. You can try taking off the gearbox and the thermostat cover to flush it out backwards with a hose.
Great learning video for me. I actually assumed a strong tell tale flow of water meant an engine has to be cooling. Good to know it may not be. Thanks stu.
Thanks stu, this helped me solve my overheating problem!
You're welcome. :)
thanks for all your time and effort. stay safe. your vidios help more than I can explain. THANKS 👍
You're welcome. :)
Very informative. I didn't know that the telltale could be working fine but the water might still not be getting to the important places. Thank you.
hi stu from all in Manchester England and thanks once again stu now thats the vid i have been waiting for your videos are an inspiration to all keep up the good work
Thanks Jimmy, glad you've been enjoying the vids. :)
Nice video Stu. I just got the cooling issue on that 25 Johnson on my new aluminum boat sorted. It had a broken thermostat.
Glad to hear you got it all fixed up Will.
what was it doing ? my johnson has a weak tell tale and nothing out the exhaust hole , I am going to check the thermostat and pull the leg , it should have a new impeller
Thank you from Trinidad & Tobago.
Welcome!
Great show as always Stu. Nice to get information so precise...thank you.
You're welcome, thanks John.
Great video. That helps me out a lot on the next time i have a issue. You have a great way of spreading advice.
Great, fantastic video. You're the best! So very helpful!
Fantastic video. Stu learnt more from 6 videos of yours then weeks of reading. Thanks mate. 😁
Thank you for this video mate, very helpful. I have a head overheating on my 150 HPDI and this has taught me a lot to go forward diagnosing!
GREAT VID. I live in one of the worst water conditions to run any boat in but just so happens that it's the best place to boat. S.W. Florida in the USA we have dirt, mud, and shells shallow water every where and a mix of fresh and salt water. In the past with older outboards I've used muradic acid to get rid of The Saltwater scale that formed inside the engine this is tricky because you cannot let it set for very long and it will do internal damage. but it did work very well to keep the engine running cool. When you get to the point where there's nothing to lose there's, nothing to lose. I have a suggestion is to dip one of those engine parts in muriatic acid and show your viewers just how fast it would work. Best Regards, and boating
Hi Tim. Yes, I'm planning to do a video comparing various cleaning agents soon. I might do it this week actually while it is topical. I'm thinking Muriatic (hydrochloric) acid, vinegar and Salt-Away. It will be interesting to see!
Excellent description Stu.
That’s why my 25hp outboard was hot on idle but pumping hot water. The water jacket was blocked. Outboard had been sitting for a while, by running in the ocean it cleared the blockage and water shot out the upper exhaust port. Thanks
Exactly the information I need! My 25hp yam has that exact engine block. Tell tail pumping very strong but I noticed the spark plugs turned blue. Thermostat was packed with sand. Suspect that is not the only issue since the previous owner melted the impeller and its housing. Hoping to find an obvious peace of plastic blocking a port. Thank you! 🇮🇪
Dude, I super appreciate your videos. Keep em coming!
Thanks Michael, glad you're enjoying them. :)
Thanks Stu. Very helpful from WA.
You're welcome George. :)
great video man thanks for the info, hello from Greece.
Thanks Tony!
Thank you so much for your wonderful video including your magic way off explanation during this Virus wish you all the best thanks again
Best explanation I’ve ever seen. Your so good at this. More please
Thank you! Will do!
my new favorite channel. Cheers!!
Keep em coming brother 💯
Will do!
Good info. No problems for me now but good to know what symptoms of future problems might mean for trouble shooting. Especially if buying a used motor. Thumbs up!
Thanks mate! :)
Great vid - thanks Stu!
As regards the purpose of the second smaller exhaust port - possibly to improve scavenging in the cylinder? I dunno. Anyway - cheers 🍻
Sounds like another good theory!
@@DangarMarine I vaguely remember a term loop charged, not sure what it does. Fantastic video though.
You need to get paint pen to mark the year and then make and hp and on the lower unit how long it is. On the motor you have laying around plus when you work on somebody's motor are working on your own motor you can write the date on it. So that whatever part of the motor you are working on. You and who ever the motor belongs to will no when it was replaced or when it was rebuilt or if you just service the motor. This is what I'm going to do so that I know. Im a first time boat owner I really like your videos . It's giving me helpful hints of what to check and look for on the used pontoon boat I just bought that has a 1990 60 horsepower Johnson pro series with three cylinder that hasn't been ran in over 6 years.
I know this is a decent thread dig but the extra exhaust port holes are bleed down ports to reduce cranking compression for easy starting.
In some cases, they are just small extensions to the top of the exhaust ports.
Perfect explanation. I was getting a poor tell-tale flow so went to the impeller. 2 blades snapped off and only 1 still in the pump housing - so how to find the lost one? Didn't understand the Yamaha cooling system as the service manual doesn't cover it. I didn't know where to begin. Based on your info I think it's likely sitting where the vertical water pipe meets the block. I'll drop the lower unit again and try running water through the flushing port to see if I can flush it out.
Really excellent explanations - thanks man!
Excellent video, many thanks.
Great video Stu very educational
Interesting to watch your clock now that you have done a tutorial on battery changing, and see how long it takes to put a video together, all you need now is a digital date movement so we can see how much time goes into doing the job.
I never really thought about it being good for that. This one actually went pretty quickly from memory as I was rushing to get somewhere else, but some take much, much longer than the 10-20 minutes they end up being.
Great video, explained the way it should be. Thank you.
Another great video - I have learned so much from them!
Saved my motor thank you brother 💯
Love your work Stu 👍🏻
Amazing videos I have some work todo but now I have a way forward. Checking head gasket and water jackets in the am
Very instructional, Stu - as usual. Armed with this I'm going to go back at my little Johnson 3.5 hp water flow issue. No water out the telltale however water is being spat back out the four little pinhole exhaust ports halfway down the leg. Somehow water must be getting pumped up to the head and although blocked in the telltale channel somehow, it is still making the journey around the jackets and back down and out. After seeing your vid I see how this might be possible.
Good luck with the diagnosis. I would push a bit of compressed air backwards through the block from the tell tale outlet.
Good idea, Stu - will try that.
Great job explaining
Good morning Stu,
Excellent video as usual, not something I need to do at this time and I'm happy about that
: ) In one of your previous videos on voltage drop and Ohm's law, you used hydrochloric acid to clean some of the corrosion off some wires, so I went in search for some at my local hardware store but they didn't have any then went to several other stores still no luck but what all of them did have was muriatic acid so when I got home I googled muriatic acid and found out that muriatic acid has another name ( hydrochloric acid ),
After running my face straight in the wall, I went back to the hardware store and bought a one litre bottle of muriatic acid and it worked like a charm, I'm guessing I failed chemistry in school LOL
Ha! Yes, they are the same thing. Don't you love things that have more than one name!
Thanks for this Stu, heaps of great info.
You're welcome Ron. Still waiting for your photo! ;)
Great great Video. Thank you so much. Nicely done. Thumbs up!
Thanks for the visit
@dangarstu been waiting for a new vid! Loving it!
Great video !!!! Funny I have a mercury 2 stroke 225 EFI and my issue is the engine is not warming up (all heads are at 90 deg).... Changed stats, checked compression, checked water pressure... And still same issue...
Hmmm, interesting problem. You could try swapping the thermostats out for higher temperature ones.
Allway's great love watching.....hello from the other side...
Hello! :)
Great video!! Thanks for sharing you knowledge!!
Wish I had seen this vid before I started trouble shooting my failed tel tail pisser. Removing the exhaust cover seemed an easier place to start than dropping the lower end for the impellers. Now I need a vid on removing snapped bolts....
Ah, bummer. On the bright side I am going to do a video on snapped bolts very soon!
Excellent man. You made my day. Thanks
Thank you budd!
For sharing with us 👍
decompression ports.. have same on my mercury cross-flow small outboard
Great video as always... thanks
This is a awesome channel!!
Thanks mate! :)
Very Nice your explanecion. ..
So thanks
Thank you for the video and I wondered if you could show us the cooling system at a 4 stroke.
Thanks mate, there are pretty similar really, no huge differences.
Thank you, very well explained.
You are welcome!
Your videos are great, keep them coming. I actually have an 50hp Johnson with bad idle and something causing some water to get on lower cylinder. Watching your video of headgasket replacement and this (even they are from yamaha) gave me some pointers what to expect when i start to tear it apart. :) There are not so many good outboard repair videos on the youtube at the moment.. Actually most of them are really dissapointing to watch. :D
Most two stroke head gaskets are pretty similar, and fortunately pretty each to do. Just take a good look for any damage to the block and head before you put it back together.
you do good stuff and explain things well. do outboards routinely do overheat alarms? with modern electronics it would not be too difficult to knock up a simple one for a few dollars.
Hi Norman, yes, they have a thermo switch that is linked to an audible alarm and they will usually go into a limp mode to cut maximum RPM but allow you to get back to the boat ramp.
Nice job on the video
Just got my Johnson 90 serviced here in Dubai. Because of the high temperature here, they told me to remove the thermostat which always are open anyhow to help the flow of water.
I presume they must have a fair bit of experience with your local climate. Things leave the factory the same whether they are going to Greenland or Dubai!
was told thermostat also serve as a restriction in flow to control rate of heat absorption of coolant past heat source. and time spent in a radiator
Brilliant mate! keep it up.
Looks like I'll be replacing my thermostat now......as a preventative measure. I has assumed a good flow out of the tube was all I was looking for. Thanks for potentially saving my engine.
Yes, thermostats are definitely something I would be changing every 3-5 years depending on use.
Dangar Marine
Haven't looked yet; I'm assuming it should be relatively the same location on my evinrude 60. Thanks for the information.
thanx for the video stu . good explanation. ever see a top cylinder scored caused by a blockage???
Normally it is from a lack of oil in the fuel, but overheating will cause expansion of the metal that can also do it, yes.
Thanks for your reply on another of your videos.... the very last section re: new thermostat..new heat sensor, new impeller, good flow up to thermostat.... pleaseeee dont be the head gasket!!!!
The port that is connected to the exhaust is autocompretion. It is working only when you start the engine. In the first stroke, when the engine start to crank, it release the comprention then the electrical engine will run early and faster.
Cool, thank you!
Thank you
top video mate, love your work!
Thank you because now I have a clue as to what's going on in my coolIng system. You explain everything so that anyone can grasp the content. Looks like the cooling systems gets a lot of mineral build up over time. Is there a way to flush vinegar or something to take out the mineral (crusty) build up to prevent Clogs?
Thanks mate. This is exactly the subject of the video I am about to upload! :)
Great video!!
Thanks ;-)
One happy Norwegian.
I’m glad I run fresh water. Salt water eats everything.
You're not wrong, salt water is very hard on boats and motor.
think you just diagnosed whats wrong with that old outboard of mine we talked about thanks brother,,
You're welcome. :)
Great vid
I think the small exhaust port in the cylinder may be an E.G.R. Port due to the location of the port. Kindly makes sense cause there’s water flowing around those ports on the cover plate. Don’t know for sure though.
Excellent vid very useful cheers😞⛵
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 tale 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.
If water is flowing up to the thermostat and the thermostat is opening it can really only be blocked cooling passages or a blown head gasket (which allows the combustion gasses to blow the cooling water out of the jackets)
Actually, I would also check ignition timing and if the mixture is lean as they can affect temperature too.
@@DangarMarine Thank you so much for your feedback. Will relay this information to my mechanic. Yes water is flowing up to the thermostat, yet i have noticed that the top 2 cylinder heads (ones closest to termostat) are the ones which are heating up the quickest. The bottom 2 feel relatively cooler. He is coming over on saturday and he wants to remove the engine block and check for water blockages in the water passages under the engine block. Does this make any sense to you ?
@@DangarMarine may i please ask you what you mean by "if the mixture is lean" what mixture are you referring to please? Also the tell tale water flow is constant, you mentioned in your video that an inconsistant water flow may mean that combustion gases are mixing with water.
Great video really learned alot.
Always watch your videos really good work and thanks for taking the time to educate boat owners. Need you to point me in the right direction 2007 optimax. Water on cylinder #2 replace water jacket and o rings still a couple off drops in cylinder good compression where to look next thanks in advance👍
Awesome thank you
Hello Dangar Stu! I'm a big fan of your channel. This video is very informative, thanks. I have a small amount of water coming into my cyclidars, mainly the top one. The head cover gasket is old but looks intact. Same with the side water gallery plate. No apparent cracks in the block. Water leaks in weather the engine runs in the water or with muffs. Where else could water leak in? My engine is a 1990 johnson 40hp 2 stroke. Would love to hear your take on this. Thanks. Keep up the good work!!
Another excellent tutorial. I have a 90 Yamaha 2 stroke. 20 years old and runs great. Just started getting hot after 10-15 minuets of full throttle. The Alarm sounds. It was fine at idle or low speed. Turned out to be popitt valve by thermostat. It was clogged with salt deposits. My question is... do you think it’s worth taking the head off just to inspect the water jackets? If corroded of clogged How to clean? What to clean with? As I said it runs excellent after cleaning popit valve. But im guessing there could be crud in there if the popitt valve had deposits. Thanks for your excellent videos and easy to understand tutorials
This video covers a few choices for cleaning the outboard. If it is running well now I would just try flushing a few times before taking the head off. The trouble with removing the head is that as well as needing a new head gasket, you don't know what else is going to happen with regards to bolts breaking etc. It needs to be really worth the risk. Here is a vid on various cleaning options ua-cam.com/video/8w_o5xB8ZFI/v-deo.html