Thanks Stu! Just started my yamaha 15hp 2 stroke after replacing the head gasket. I'm alone, on anchor in Panama and you were my only friend for the project. Obviously it went well. Living on a sailboat in remote places, I must learn new skills every time something breaks. Thanks to people like you, it's become quite easy. Liked and subscribed!
I am 68. Been an auto mechanic, 62B10 heavy equip. mech. & small engine mech. I knew nothing about out board engines until I found your channel! Thank you so much!
I recently purchased a seized 55hp Sea King/Chrysler outboard for cheap and while I am mechanically inclined, I had never worked on a boat engine before. I started watching your videos last week and while I have done most things right so far, I have also learned a lot that will help me with the rest of the repair process. Hopefully pulling the head won't be necessary but if so, this great information will help!
Stu - as always, thanks for keeping these old videos around. Found out this last week my 1973 Johnson 50hp is either dealing with a head gasket problem or a water jacket issue. If it's been sitting for several days, it starts and runs without issue. But if it's been run hard and warmed up, it doesn't want to restart. I took it to the shop and they cleaned and tuned the carbs but still couldn't get it to idle. After it had been running for a while, they pulled the plugs and saw that they had water on them. So there's either a leaky gasket or crack somewhere. As AvE would say, it's already fuckered so I can't make it worse so going to pull the water cover and head and see what I can see. Replace both seals and then reset the timing and see what we get ...
@@DangarMarine yeah it certainly seems like it. If the head gasket has an issue, could it still compression test ok? The shop said both cylinders tested at 100psi cold. Not great but not terrible.
Changed the thermostat and cleaned out the water pump area. Was overheating constant. Now she runs like a dream. Yamaha 80hp 2 stroke on a Shetland black hawk. Your channels amazing mate.
Dangar Marine well thanks to your videos we where able to do it in the morning and take her out the rest of the day. (Loch Lomond Scotland) the overheating was caused by muscles growing in the thermostat from previous owner never flushing her out.
Hi Stu I had this on a 1990 Johnson 40 hp 2stroke and I took off the bottom ring to get bottom bolts accessible. Not that I’m saying you’re doing it wrong. After all the end result is what we are after. Thanks for all you do to help other boaters, you’re fan from Missouri. P.S. The motor would run and miss and sneeze after looking at vacuum leaks mixture settings I found the VRO system was one of the problems causing plugs to foul quickly so I bypass it. It was mixing around 20 to 1 and it couldn’t be fixed. I tested it by how much oil used to a gallon of fuel. Also resetting the timing to the factory marks and fine tuning the carburetors Helped as well.
Yes, taking the lower cowling off can really help with access in many jobs. The trouble with these older salt water boats is that they are some of the most corroded bolts so you always take the risk of something snapping. It isn't hard to see how you go the fouling at 20:1, glad you've got it running nicely now. :)
Thank you. I bought a very similar one which came with a blown head gasket, without a thermostat and temperature sensor. You have helped me a lot. 👍👍👏👏👏
Awesome as always. When I couldn't reach the lowest two bolts on the head cover to remove it, (they were really stiff & started to burr over with spanner use) I actually drilled two 22mm holes in the outer casing to provide access to them. It seems a bit radical, but I got 2 grommets to fill the holes for water-tightness, so it should be ok. I then could use a socket to remove them (one broke close to the head, which was a whole other adventure!). However, I now have much more chance of tightening all the bolts accurately with a torque wrench...
Cheers 🍻 and ThankYou very much for the details that oftentimes these ‘do it yourself’ videos do not include, well done!!!. MoN this Rocks!! My 07’ 25mlh needs that completed soon at 91/90psi
Nice vid Stu, just got my head gaskets in the mail from MarineEngine to do my old 100hp Evinrude, It's amazing how often you've upload videos of the exact thing that planned to do my outboard its a big help thanks
Just got turned on to your site and I appreciate your teaching ability. Head and shoulders above many of the sites I see on UA-cam. Thank You very much.
Brilliant teacher, I have always had no confidence with Engines , You give me confidence, alas I do not have the Tools you have but you explain things very well . Thanks .
I lost it at "couldn't find a longer straight edge, so I guess we'll have to use this one" (holding a yard long ruler) 😂 Gotta love the dry-pan aussie humour! Great videos, keep it up!
Great video Stu. I'm always nervous when removing those head bolts and still nervous when torquing them down. I've broken them in both instances. When it's all back together with no broken fasteners I usually celebrate with a much needed beer!
Yeah, always use new head bolts. Once installed (torqued to specs), they should never be used again. (they stretch after a time of running. it's only a few thousands, but that's all it takes) Everytime I've seen a head bolt snap going in, it was with a used one... I've never seen a new one break on install, but maybe I've just been lucky for 40 years. lol
Worse nightmare is removing head or even exhaust bolts from engines that lives moored in salt water or the ones that's been used in salt water and never flushed with fresh water soon after returning from boating. Salt will seize anything badly. It's a good thing to slight oil cleaned or new bolts, torque them to specs, should come out without any issues if a latter removal is required...
good trick with the hand torque method is to use a scale on the end and read where it clicks, and do the same for the hard to reach one (same length wrench of course). On some outboards dropping the lower cowling gives better access - thanks for the vid!
Interesting tip about putting oil on the bolts so they don't bind and give a false reading on the torque wrench, I'm still working on the 50HP Mercury but the delay is that I'm also working on the fiberglass repairs to the boat it will be going on, finally got the stingers and transom dry mounted and there a perfect fit and still waiting on the flywheel puller to arrive so I can properly repair the wires coming from the stator, which at that point I will mesure properly before re-installing it
Great video. One comment about oiling head bolts: I was told that too much oil on the head bolt (or on the internal threads of block) can result in problems. For example if there's a pool of oil at the bottom of the bolt hole, and the bolt hits the oil - there's nowhere for that oil to go and it can throw off the torque (ie false reading because of the oil stopping the bolt) OR, more seriously, it can strip the threads on the bolt because of high hydraulic pressure. Perhaps a simple warning not to over-lubricate is what I'm getting at. Yes, oil the threads - but sparingly instead of liberally. Thanks for all your great videos!
Tip on removing corroded head bolts: Just after you break them loose - work them back and forth a bit to break up the corrosion. 1/4 turn back and forth 5-6 times will break most of the corrosion on the threads into a fine dust that is much less likely to bind the bolt, and cause it to snap. Penetrating oil after you break up the corrosion helps if the oil will flow into the threads.
@@jazldazl9193 If it looks extra dicey, then you can always heat the crap out of it before you get started. This also helps to break up any rust or other corrosion, and tends to loosen things up quite a bit especially with dissimilar metals that expand at different rates. One other thing to be aware of when dealing with aluminum. Check your bolt hole carefully after you remove the bolt... frozen bolts tend to take a good portion of any aluminum threads out with them. Certain Ford engines have this problem with a specific spark plug that no one ever wants to change, and then they start blowing out spark plugs. It's best to find this out and Helicoil it before you are redoing a head gasket job because the bolts keep coming loose.
Good Video bringing up lots of the tricks and pitfalls, I also watch Kodibas up in Alaska who like you mentions the gotchas and pitfalls while fixing up outboards many fisherman and hunting up in the cold north.
Great video. The cylinder differencal you prove that the labyrinth's were sealed between cylinders. The thermostat being out could lead the top cylinder burning cleaned. Bottom one carbonized. The back firing a sheared key on the flywheel or magnets that have moved from the flywheel. They are glue in.
Hey John. Definitely going to be pulling the flywheel on this outboard as the next port of call. I've had a sheared woodruff key on a flywheel recently so I'll be checking this one straight away. The timing linkage can't be adjusted far enough out to cause backfiring like that.
I've watched this video multiple times and read through all 310 comments before I reassemble my 1991 Yamaha 115 cylinder head that had a thermostat bolt break in it, then the extractor broke despite my best efforts. I have a new cylinder head, cover and gaskets and worked very carefully to clean the block with scraping and then carefully and diligently used a bench stone to clean the remainder. I have checked and rechecked for warpage (over stoning) with an abnormally long straightedge ;-) My SELOC manual states in BOLD text in multiple sections NOT to use sealer. Stating that an even coat is near impossible to obtain and "Never, never use automotive type head gasket sealer. The chemicals in the sealer will cause electrolytic action and eat the aluminum faster than you can get to the bank for money to buy a new cylinder block." All of this conflicting info is causing my over analytical mind to go into convulsions! Since I live in Alaska and can't seem to get Hylomar and Permatex High Tack spray-a-gasket Adhesive Sealant rated to 450 degrees F. (232 C.) is the closest I can find I think I will just opt to go dry. The manual does call for Permatex on both side of the thermostat gasket so I will use the High-Tack there. The next thing to agonize over will be how to set all the bolts for new cover and top. I did get all new bolts and even replacement washers. I think I will clean the threads into the block and use the blue Loctite method, decreasing the torque value by 25% as stated here on Anti-Seize Technology site under FAQ: www.antiseize.com/Content/Images/uploaded/torque_specifications.pdf Stuart, thank you so much for all the videos you have created. Your knowledge and humor have been an invaluable asset to me. I gave you a FB recommendation, subscribed, and ordered a bunch of DM swag from your site so that me and the family can stay warm as we drift aimlessly about as I bollock-up my kicker! I lament that my late father never got the chance to watch your videos. He lived in Australia for a year and had a 39' sailboat in Washington state. He would have loved your channel! He would want me to quote Wind in the Willows and what Water Rat said to the Mole: "Believe me, my young friend, there is nothing--absolutely nothing--half so much worth doing as simply messing about in boats." Cheers Stuart! ~Ben (ps I just signed up as a Patreon, keep up the good work and have a Coopers on me, Mate!)
I always see people using bench stones, did you use it on the block with the pistons in? I am afraid of getting metal scrapings in the cylinders by doing this.
Good job...I noticed you put something on the cylinder head bolt threads while reinstalling..In the U.S. mechanics often use a non hardening gasket sealer such as permatex..It prevents salt intrusion on the threads more effectively than greese.Also heads that are slightly warped can often be planed down at a machine shop..or even by hand by using fine Emory cloth sheets..with a figure eight motion..On small engines like this one..(old school) .Another old school trick is remove the inards of the thermostat so you have some restricted flow of the water so it picks up the heat..and yet you don't have the worries of a stuck thermostat..The total removal of the thermostat allows too quick a flow..and might explain the top cylinder carbon.. Carburetion adjustments and cleaning should do the trick unless the intake reed valves are worn out..rare but can cause the issue noted..Disclaimer..The correct repair on the cylinder head cooling is replace the thermostat with a new one..especially if it's a fresh water motor or in a cold climate.There are products to flush through the motor and remove...desolve salt..
Thanks Will, I'll be sure to check that video out. I was thinking of doing something a bit similar soon to go with the winterisation video but you beat me to it! ;)
Gearwrench does have ratchet wrenches with reversible drive. I have a few and the head is usually still small enough to get in tight spaces. Little pricey though. Great video as always mate.
Great and informative are the old 65hp 3cld Mercurys easier to replace the Cooling Head without taking Cylinder head off and having to reseal and replace the cylinder head Gasket.
Nice video but you can tell the guy is backyard trained no factory training of any kind. Which is good down to earth personality not stuck up or tryin to talk a big thumbs up bro!
I changed the headgasket on my Mariner (yamaha engine) 30hp last summer. The gasket was blown and had less than 50% compression than cylinder 1. Snapped two of the headbolts and it was a bitch to fix it. Luckily it was much material left on the cylinder so i could drill the old remains out and make new threads. Now it runs like a champ!
There are many situations this does not work, simply because the bolt has a flange behind the hex. Your only options then are to cut off the bolt to get your wrench back, or cut the wrench apart to free the bolt. Cutting the bolt is usually the cheaper option, but not always!
Great video. I have a suzuki dt25 1984 and its really hard to start it when cold. When hot engine starts very easy. I am thinking the CDI causes the problem. If that doesnt change the problem i will take a compression test and move onto a head gasket replacement since the outside seems rusted.
In my apprenticeship the instructors always said the torque settings were for 'dry on dry' threads and to never use lubricant on the threads because you will over torque the threads, plus the bolts can vibrate loose easier due to the low friction. Where I work now we use blue Loctite or 'thread sealer' that looks like ATF and sets like a gell and the torque settings are all redone to allow for the fluid being on the threads. Looking at the tables for a 'dry' thread use and a 'sealed' thread use, 12mm bolts with fine threads are roughly 15Nm lower for wet threads, 10mm are 12Nm less, 12mm course thread are 10Nm less and 10mm are 8Nm less. Actually , those are for 'screws' , we don't put thread lock on bolts, we use the sealer on the shank of the bolts and none on the threads, but that is being picky:-) - anti vibration is by spring or star washers.
Hey Ron, I find that a lot of service manuals will specify what conditions their torque settings are under. For example, the Evinrude specified dry but the Yamahas will tell you to add oil so I presume both these stated figures take this in account. As a result oiling the Evinrude will probably give you the wrong result. Interesting point about sealing the thread to stop corrosion getting in there. That sounds like it could save a whole lot of headache down the track!
Sealing the bolts doesn't always work, the holes have to be blind . The ratchet spanner bit about them getting caught is recoverable if you push the spanner head onto the shank of the bolt and then use a normal spanner to refit the bolt to get clearance back. but yes - the torque figures in manuals are for the lubricated/not lubricated thread as specified.
Ron Powell your instructor was right. Been working on engine for many years. But you also have to understand it's like cooking. People are taught one way the "basic way" and then over years everyone builds there own way of doing so. But I would say a huge no no on the oil on threads. If you clean the threads like he did then clean the threads in head you need only lock tite to get it rite all the bolts WILL vibrate out the side of the motor especially on a 2 stroke.
thanjs for the video but now i am in the middle of fixing one AND I HAVE TO WAIT for another video so i can fix it, Just kiddingn and really enjoy the videos keep them coming
Thanks for the Video, I'm working on changing the cylinder head and head gasket on my 90hp yamaha 2 stroke and ive been having some trouble removing the old gasket material. Ive been using plastic scrapers and a rubber wheel for removing decals off of vehicles that attaches to my drill. I still have some material left and I saw that you used a brass wire wheel for your process so i purchased one and tested on the old cylinder head but it seems to be sratching the surface so i was hoping you could suggest exactly what you used to accomplish this. Thanks in Advance Wes
Sanding the block with the pistons in is a bad idea, right? I was thinking about doing it with the block still being on the engine in vertical so if anything falls off does it does not get on top of the pistons or deeper into the cylinder.
I have a 15hp yammy that sometimes revs out and mostly won't, this started after replacing a stuck thermostat, it was a $100 motor that seems to have had zero maintenance for its 25 year life, I figured for a $100 it was worth it as I do all my own work. After cleaning carb, and replacing the thermostat I tasted the tips of the sparkplugs and found one was salty indicating water on the plug. It would also occasionally be seized after standing for a day or two but loosened up easily, also indicating water in the cylinder. The strange thing is compression was 125 even on both cylinders. I popped the head off to find the water jacket almost completely blocked, yet the head gasket doesn't look blown. I have ordered a new head gasket and given the cylinders a light deglazing with 320 emery paper on a drill to return some cross-hatching (I have had luck in the past doing this on small 2.5hp tohatsu/mercury's) and hopefully, this will sort the issue. My only hope is that the water is not from a crack somewhere I haven't found yet.
Great video your description and explaining is so easy to understand - I’m new to boat engines very familiar to 4 stroke car engines . So you are really helping me to get confident to get a boat and engine and keep it running great 👍 can you recommend a good 100hp outboard and/ or bigger to start my boat life?
Nice calendar! Or poster back there... I'm about to pull the cylinder heads off my 1994 200 hp Yamaha. I hope I can get all the bolts out without snapping one off!
Hey Stu, I am rebuilding an old 15 hp Yamaha, I've replaced cylinder bores, pistons, piston rings and all bearings to the power head. I can't find information on how to "break in" a "new" outboard (two stroke), maybe you could do a video about that. Or maybe someone who knows will reply to this comment. Thank you. Cheers
so just for the first 3 gallons use a 25:1 mix (which is simply a pint to 3 gallons). no stabilizer just gas and oil. make sure the throttle is down to a crawl when you first fire it up and just let it idle for the first 10 minutes. don't touch it! let the rings wear in as best they can. then take it out on the water. if you boat is light, smoothly but quickly give it full throttle to plane off, then back off to 1/2 throttle. if the boat is heavy, don't go above 1/2 throttle for the first hour and vary the speed every 5 minutes or so very slightly. if you are out of gas by now, refill with 50:1 for the rest of break in.the second hour you can give it 3/4 throttle every now and again, but continue to vary the speed. from hours 3-10 give it full power every few minutes, but only for 30 seconds or so. BE GENTILE the first 10 hrs. after break in is done, check the plugs and lower unit oil for metal and / or water intrusion. you can now use 100:1 fuel ratio, but be sure to use marine stabilizer each tank for the life of the motor to prevent internal corrosion. its especially important with 100:1 mix as thats not enough oil to protect the crank from corrosion when not in use.
Gday mate good video ,when i did my 50hp triple i changed the sacraficial anodes in the block ,i didnt see any in this 20 do they not put them in smaller engines ? i also cleaned as much of the water jacket on the block as i could with a wire brush on a dremel tool handy piece of kit that anyway 2 strokes as you say are fairly easy to work on
Hi mate. All outboards are a bit different with the location of the internal anodes. Some are under the head, some are accessed from the side of the block. They will all generally have at least one though.
Nice video Stu, when changing cylinder head gaskets I usually remove the entire powerhead, take advantage to clean all water paths, decarbon piston heads, exhaust area. Install a new lower base gasket with s slight grease coating at both sides, and torque to specs. that's to be able to remove the powerhead again without harimig the gasket My motor has 4 lower head bolts impossible to be torqued with a torque wrench if powerhead reamins screwed on its base.I'm a manic about torquing all head bolts to same torque spec whichever they are. Other issue, on 2 strokes 2 cylinder motors have never seen both plugs to come out in same clean cond, the lower one usually comes out bit darker than the upper one, and that's on new out of the box motors with few run hours on them., seems it's the nature of the beast. When you torque a cylinder gasket with a torque wrench, say needs to be torqued back to 25 NM, you torque it in a single torque straight to 25 NM or in a 2 step process, say 13 on first one, 12 on the second torque adjustment.?
Thanks for these fantastic videos. I watch them for hours. Please produce a video or link to how I can reseat the heads on my year 2000 Johnson 115 2-stroke motor. It is leaking slightly at the top inside of the starboard head. It uses sealant rather than a gasket and I need to know the best sealant to use, exactly where and how much to put on. Thanks again.
Hey buddy I just test drove a motor that I traded for some work. 60 evinrude, It's has compression of 90psi,89psi,29psi on bottom cylinder so I've started taking the head of and unfortunately 5 bolts snapped. I was gently as I could pulling them out. Well just the start of a big project. I hope you don't mind me asking questions In future. Anyway beer getting warm trying to get this head off now By the way trying to get me a shirt funds are tight save a spot on top right of board for me
Hey Bryan, it's pretty common for bolts to snap on old outboards like that, but as you say, it is a big project and one that you will enjoy with the right approach. I'll save a spot for a photo of you with your outboard. :)
Thank you, I am taking a 25 hp Nissan apart due to top head gasket failure, leading to top over heating, loss compression, 85 top and 125 bottom. Top cylinder wall scratched lightly. I wish I could bring both to 120 to 125.
You might find that with a light hone and new rings the compression comes back up. I would also get the head machined before re-installing with a new head gasket.
Thank you so much for the great suggest, yes , l ordered new rings, head gasket, mid sect. gasket and new impeller. All the bearings are still tight and no discolor or burn marks.
How much water should I expect to see coming out of the exhaust ports on an '81 90 hp Evinrude? I replaced the head gaskets thinking that would solve the problem but still getting some water blowing out. It is more of a mist than any kind of flowing water. Everything with the motor seems to be running as it should, no overheating, no fouled spark plugs. Do get some unburnt oil dripping down the lower after trolling for the day which I think is normal.
It certainly wouldn't hurt. I don't worry so much about this crud as I would about metal filings from grinding for example, but its not a bad idea to stuff some rag in there before you start.
Hi Stu, been reaching these head water passage videos again. I'm diving into this for the first time on a 3hp Evinrude 2 stroke. You mentioned the step on having the carb shutters wide open to preform a compression test. I think the reason for this is to rule out defective reed valves. It may affect the readings. I'm new at this internal stuff but thought I would point out the reeds may affect compression?
I have a 1977 Evinrude 25HP and the compression readings I got were 50PSI on the top cylinder and 70PSI on the bottom cylinder..... do you think a leaking head gasket could cause that much of a compression drop or is my problem likely worn piston rings or something "catestrophic" as you put it in the video. If the piston rings are worn I am wondering how do I really tell or if you have a video to diagnose low compression. Thank you for the videos. Have been watching a lot of them lately while trying to figure out how to get this outboard running. Thank you.
A quick shot of oil in the plug hole and re-do the compression test. A marked rise in figures usually indicate worn rings. Not a fail safe method, but a pretty good indicator in general.
Around 180 grit wet & dry silicon paper on a wet flat surface (glass) in a figure 8 pattern is preferred ! method, wire buffing a cylinder head not best practice, and make an allowance for possible left over asbestos gasket material on machined surfaces and wire buffing will spread the fibres!
Stumbled across you channel and learned quite a bit. Have water coming out of my spark plug hole so changed the water jacket gasket without success as there's still water. Pull it all apart and try again. Hope it's not a cracked head. Any other pointers? Thx!
@@DangarMarine Yeah, replaced the head gasket and water jacket and still get water coming out of the lower spark plug hole. Any use dropping the lower unit and replacing the impeller or is the head cracked. I don't see that its cracked. Thanks!
@@gmoney2369 Working on old Yamaha dirt bikes back in the 1970's, if a head bolt felt like it wouldn't break free, we would gently heat it with a torch (go easy man - you can warp the head FAST like this if you aren't careful!) and gently tap it several times with a plastic mallet. Spray with WD40, wait a few minutes, tap and spray again, repeat until the bolt has cooled down. Try again. TAKE YOUR TIME. The heating/cooling cycle expands/contracts the corrosion between the head engine block and bolt holding the head on, and allows the WD40 to penetrate better. Repeat as many times as necessary... it almost always works, but it sometimes takes many tries. Allow the head/head bolt to COMPLETELY COOL ON IT'S OWN (don't try to cool it down any faster!) before making another attempt!!! It's better than snapping a Head bolt... ask me how many times I found out. lol
@@gmoney2369 I recently had one break on a 1998 Yamaha C60. It was about 1/8" below flush with the crank case, and I didn't want to risk breaking an EasyOut in it and making things even worse. (they should have called them "Easy-to-Break") We welded a nut to it, and along with a little heat, and a lot of patience and penetrating oil, it came out. Hope this helps someone else in that predicament.
Have a 70 Yam. 2 stroke..runs great but overheats at WOT not at slow 6knts. Thermo good. Opened head and saw 2 pieces of the cylinder stiffner broke. It appears they could restrict water in the cooling channels around the cylinders. Ran it without thermo and still over heat and showing 220f on the upper of the 3 cylinders. I'm replacing the head gasket (thanks for this great video) and hope it was the stiffners pieces that caused the restriction. The tell-tale was strong. Think those pieces could have restricted the flow enough to overheat? Thank you
I was surprised after seeing vids of people removing the head like you did and looking at the pistons ect...to realize my 50 merc is a "headless" outboard. Its the strongest stock 50 2 stroke ever made at 59ci(yamaha is like 42) which I'm happy about but I think it sucks I can't remove the head like the other motors. Apparently if I ever want to rebuild this motor I have to find a very knowledgeable machine shop who can bore "blind cylinders". Have you ever had to mess around with a headless outboard before, lol?
I can't say I have worked on. It sounds like it should be quite strong but I guess you need to split the crankcase and pull the pistons out that way if they need and attention. As you say, most machine shops probably don't have much experience with boring them. Fingers crossed it will just keep going!
Hey Stu great video very helpful i’m currently in the process of replacing the pistons in my 2 stroke yammy you wouldn’t happen to have a video with some tips an tricks on how to do that?
Would an exhaust leak from head gasket cause air/ exhaust to come out the tell tale? I change the impeller and gasket check the key way for impeller made sure it lined up with water tube that goes up to motor.. if I take the thermostat off and run the engine, water will come out the thermostat housing with some exhaust and out of the tell tale at a good clip for long time.. as soon as I put the thermostat back in I start the engine and water will come out the tell tale for about 20 seconds and then air or exhaust comes out the little pee hole.. don’t know what else to try.. any help would be appreciated.. thanks
@@DangarMarine thanks for the quick response I have nearly tried everything.. I submerge the lower unit in a 50 gallon drum I took off the thermostat and let it run for 5 minutes.. water was gushing out the thermostat housing and tell tale.. I turned it off put the thermostat housing back on and started it again.. only a good stream from tell tale for about 30 seconds.. as it started heating up the stream kept decreasing until noting but air was pushing out the tell tale… idk what else could be causing this.. has me clueless… thank for ur quick response it’s appreciated.. great videos thank you
Stu, I have a Johnson 50 hp. I see some white stuff (salt? corrosion?) around the head gasket near the lower cylinder. Is this the sign that something is wrong or normal occurrence in salt water? Motor starts easy and runs fine. Thanks for the great videos!
Hi Brian, you do see that and it isn't necessarily a sign that the head gasket needs replacing. If you still have good compression I wouldn't worry too much.
Thanks Stu! Just started my yamaha 15hp 2 stroke after replacing the head gasket. I'm alone, on anchor in Panama and you were my only friend for the project. Obviously it went well. Living on a sailboat in remote places, I must learn new skills every time something breaks. Thanks to people like you, it's become quite easy. Liked and subscribed!
I am 68. Been an auto mechanic, 62B10 heavy equip. mech. & small engine mech. I knew nothing about out board engines until I found your channel! Thank you so much!
These are easily the most helpful marine vids on UA-cam. Thanks for making them. :)
You're welcome Conner, glad you like them. :)
@@DangarMarine your thoughts on prudence of gasket sealant?...
I recently purchased a seized 55hp Sea King/Chrysler outboard for cheap and while I am mechanically inclined, I had never worked on a boat engine before. I started watching your videos last week and while I have done most things right so far, I have also learned a lot that will help me with the rest of the repair process. Hopefully pulling the head won't be necessary but if so, this great information will help!
Hey Matt, glad to hear your restoration is progressing nicely. Good luck with the rest of it!
straight up your comment about rachetting spanners and about oiling the head bolts for proper torque are absolute key! Thanks again!
Thanks James!
Thanks, I swear Dangar Marine's videos are keeping my 1983 Mariner 25M running!
Thanks Stu for all these videos. Working on an old 2 stroke at the moment and watching your posts is great.
You're welcome John, good luck with your outboard. :)
Once again, a brilliant video, you’re so easy to watch, down to earth, and extremely informative
Stu - as always, thanks for keeping these old videos around. Found out this last week my 1973 Johnson 50hp is either dealing with a head gasket problem or a water jacket issue. If it's been sitting for several days, it starts and runs without issue. But if it's been run hard and warmed up, it doesn't want to restart. I took it to the shop and they cleaned and tuned the carbs but still couldn't get it to idle. After it had been running for a while, they pulled the plugs and saw that they had water on them. So there's either a leaky gasket or crack somewhere. As AvE would say, it's already fuckered so I can't make it worse so going to pull the water cover and head and see what I can see. Replace both seals and then reset the timing and see what we get ...
With water on the plugs it definitely sounds like your problem. Good luck with the job!
@@DangarMarine yeah it certainly seems like it. If the head gasket has an issue, could it still compression test ok? The shop said both cylinders tested at 100psi cold. Not great but not terrible.
Changed the thermostat and cleaned out the water pump area. Was overheating constant. Now she runs like a dream. Yamaha 80hp 2 stroke on a Shetland black hawk.
Your channels amazing mate.
Nice work mate, glad to hear you got it running nicely again. :)
Dangar Marine well thanks to your videos we where able to do it in the morning and take her out the rest of the day. (Loch Lomond Scotland) the overheating was caused by muscles growing in the thermostat from previous owner never flushing her out.
Hi Stu I had this on a 1990 Johnson 40 hp 2stroke and I took off the bottom ring to get bottom bolts accessible. Not that I’m saying you’re doing it wrong. After all the end result is what we are after. Thanks for all you do to help other boaters, you’re fan from Missouri. P.S. The motor would run and miss and sneeze after looking at vacuum leaks mixture settings I found the VRO system was one of the problems causing plugs to foul quickly so I bypass it. It was mixing around 20 to 1 and it couldn’t be fixed. I tested it by how much oil used to a gallon of fuel. Also resetting the timing to the factory marks and fine tuning the carburetors Helped as well.
Yes, taking the lower cowling off can really help with access in many jobs. The trouble with these older salt water boats is that they are some of the most corroded bolts so you always take the risk of something snapping. It isn't hard to see how you go the fouling at 20:1, glad you've got it running nicely now. :)
Thank you. I bought a very similar one which came with a blown head gasket, without a thermostat and temperature sensor. You have helped me a lot. 👍👍👏👏👏
Glad to have helped. :)
Awesome as always. When I couldn't reach the lowest two bolts on the head cover to remove it, (they were really stiff & started to burr over with spanner use) I actually drilled two 22mm holes in the outer casing to provide access to them. It seems a bit radical, but I got 2 grommets to fill the holes for water-tightness, so it should be ok. I then could use a socket to remove them (one broke close to the head, which was a whole other adventure!). However, I now have much more chance of tightening all the bolts accurately with a torque wrench...
I think that is a good way to go, nothing wrong with drilling to give access.
Cheers 🍻 and ThankYou very much for the details that oftentimes these ‘do it yourself’ videos do not include, well done!!!. MoN this Rocks!! My 07’ 25mlh needs that completed soon at 91/90psi
Glad to help!
Nice vid Stu, just got my head gaskets in the mail from MarineEngine to do my old 100hp Evinrude, It's amazing how often you've upload videos of the exact thing that planned to do my outboard its a big help thanks
I'll make sure I never upload a video on how to deal with a fractured crank case then just to keep you safe. ;)
Just got turned on to your site and I appreciate your teaching ability. Head and shoulders above many of the sites I see on UA-cam. Thank You very much.
You're welcome Michael, glad you like the vids.
Brilliant teacher, I have always had no confidence with Engines , You give me confidence, alas I do not have the Tools you have but you explain things very well . Thanks .
I lost it at "couldn't find a longer straight edge, so I guess we'll have to use this one" (holding a yard long ruler) 😂 Gotta love the dry-pan aussie humour! Great videos, keep it up!
Thanks mate. :)
I just found your channel and I love it, I use to work at a Yamaha dealership but I wasn't a mechanic but I wanna be one day I love working on boats
You should go for it Tony, life's too short not to do the things you love. :)
@5:50 You removed the coils and put back the bolts into their threaded hole. You are a great professional.
Another very well explained, step by step, well done again !
Thanks mate. :)
Great video Stu. I'm always nervous when removing those head bolts and still nervous when torquing them down. I've broken them in both instances. When it's all back together with no broken fasteners I usually celebrate with a much needed beer!
Hey Jack, interesting that one broke putting it in. I wonder if the thread needed cleaning first or whether it was a faulty bolt.
Yeah, always use new head bolts. Once installed (torqued to specs), they should never be used again. (they stretch after a time of running. it's only a few thousands, but that's all it takes)
Everytime I've seen a head bolt snap going in, it was with a used one... I've never seen a new one break on install, but maybe I've just been lucky for 40 years. lol
Worse nightmare is removing head or even exhaust bolts from engines that lives moored in salt water or the ones that's been used in salt water and never flushed with fresh water soon after returning from boating. Salt will seize anything badly. It's a good thing to slight oil cleaned or new bolts, torque them to specs, should come out without any issues if a latter removal is required...
good trick with the hand torque method is to use a scale on the end and read where it clicks, and do the same for the hard to reach one (same length wrench of course). On some outboards dropping the lower cowling gives better access - thanks for the vid!
Interesting tip about putting oil on the bolts so they don't bind and give a false reading on the torque wrench, I'm still working on the 50HP Mercury but the delay is that I'm also working on the fiberglass repairs to the boat it will be going on, finally got the stingers and transom dry mounted and there a perfect fit and still waiting on the flywheel puller to arrive so I can properly repair the wires coming from the stator, which at that point I will mesure properly before re-installing it
Hey Adrien, sounds like your project is progressing nicely. I'd like to do some more vids on repairing fibreglass hulls.
You make it look so easy...Great video. Hope this will be an easy fix. Stay dry. Thanks for posting.
Great video. One comment about oiling head bolts: I was told that too much oil on the head bolt (or on the internal threads of block) can result in problems. For example if there's a pool of oil at the bottom of the bolt hole, and the bolt hits the oil - there's nowhere for that oil to go and it can throw off the torque (ie false reading because of the oil stopping the bolt) OR, more seriously, it can strip the threads on the bolt because of high hydraulic pressure. Perhaps a simple warning not to over-lubricate is what I'm getting at. Yes, oil the threads - but sparingly instead of liberally. Thanks for all your great videos!
Thank you vary much you are getting vary popular in the states especially in Florida and the coastal s.
You're welcome Gerald. That sounds like a really good reason to come to the US for a meet up. ;)
This video couldn't have come at a better time haha, waiting for my head gasket to come in the mail.
Nice one! :)
Tip on removing corroded head bolts: Just after you break them loose - work them back and forth a bit to break up the corrosion. 1/4 turn back and forth 5-6 times will break most of the corrosion on the threads into a fine dust that is much less likely to bind the bolt, and cause it to snap. Penetrating oil after you break up the corrosion helps if the oil will flow into the threads.
good advice but when they wanna go they SNAP
@@jazldazl9193 If it looks extra dicey, then you can always heat the crap out of it before you get started. This also helps to break up any rust or other corrosion, and tends to loosen things up quite a bit especially with dissimilar metals that expand at different rates.
One other thing to be aware of when dealing with aluminum. Check your bolt hole carefully after you remove the bolt... frozen bolts tend to take a good portion of any aluminum threads out with them. Certain Ford engines have this problem with a specific spark plug that no one ever wants to change, and then they start blowing out spark plugs. It's best to find this out and Helicoil it before you are redoing a head gasket job because the bolts keep coming loose.
Good Video bringing up lots of the tricks and pitfalls, I also watch Kodibas up in Alaska who like you mentions the gotchas and pitfalls while fixing up outboards many fisherman and hunting up in the cold north.
So dang good. Nicely structured and great clear explanations. Thank you
Great video. The cylinder differencal you prove that the labyrinth's were sealed between cylinders.
The thermostat being out could lead the top cylinder burning cleaned. Bottom one carbonized.
The back firing a sheared key on the flywheel or magnets that have moved from the flywheel.
They are glue in.
Hey John. Definitely going to be pulling the flywheel on this outboard as the next port of call. I've had a sheared woodruff key on a flywheel recently so I'll be checking this one straight away. The timing linkage can't be adjusted far enough out to cause backfiring like that.
I've watched this video multiple times and read through all 310 comments before I reassemble my 1991 Yamaha 115 cylinder head that had a thermostat bolt break in it, then the extractor broke despite my best efforts. I have a new cylinder head, cover and gaskets and worked very carefully to clean the block with scraping and then carefully and diligently used a bench stone to clean the remainder. I have checked and rechecked for warpage (over stoning) with an abnormally long straightedge ;-) My SELOC manual states in BOLD text in multiple sections NOT to use sealer. Stating that an even coat is near impossible to obtain and "Never, never use automotive type head gasket sealer. The chemicals in the sealer will cause electrolytic action and eat the aluminum faster than you can get to the bank for money to buy a new cylinder block." All of this conflicting info is causing my over analytical mind to go into convulsions! Since I live in Alaska and can't seem to get Hylomar and Permatex High Tack spray-a-gasket Adhesive Sealant rated to 450 degrees F. (232 C.) is the closest I can find I think I will just opt to go dry. The manual does call for Permatex on both side of the thermostat gasket so I will use the High-Tack there.
The next thing to agonize over will be how to set all the bolts for new cover and top. I did get all new bolts and even replacement washers. I think I will clean the threads into the block and use the blue Loctite method, decreasing the torque value by 25% as stated here on Anti-Seize Technology site under FAQ: www.antiseize.com/Content/Images/uploaded/torque_specifications.pdf
Stuart, thank you so much for all the videos you have created. Your knowledge and humor have been an invaluable asset to me. I gave you a FB recommendation, subscribed, and ordered a bunch of DM swag from your site so that me and the family can stay warm as we drift aimlessly about as I bollock-up my kicker! I lament that my late father never got the chance to watch your videos. He lived in Australia for a year and had a 39' sailboat in Washington state. He would have loved your channel! He would want me to quote Wind in the Willows and what Water Rat said to the Mole: "Believe me, my young friend, there is nothing--absolutely nothing--half so much worth doing as simply messing about in boats." Cheers Stuart! ~Ben (ps I just signed up as a Patreon, keep up the good work and have a Coopers on me, Mate!)
I always see people using bench stones, did you use it on the block with the pistons in? I am afraid of getting metal scrapings in the cylinders by doing this.
Hi Stu, You need to do a video on changing reeds on a 2 stroke. I'm sure there is a bunch of folks who don't know what these are
That will be the next job on this Yamaha that is running lean, video up on the weekend!
Good job...I noticed you put something on the cylinder head bolt threads while reinstalling..In the U.S. mechanics often use a non hardening gasket sealer such as permatex..It prevents salt intrusion on the threads more effectively than greese.Also heads that are slightly warped can often be planed down at a machine shop..or even by hand by using fine Emory cloth sheets..with a figure eight motion..On small engines like this one..(old school) .Another old school trick is remove the inards of the thermostat so you have some restricted flow of the water so it picks up the heat..and yet you don't have the worries of a stuck thermostat..The total removal of the thermostat allows too quick a flow..and might explain the top cylinder carbon.. Carburetion adjustments and cleaning should do the trick unless the intake reed valves are worn out..rare but can cause the issue noted..Disclaimer..The correct repair on the cylinder head cooling is replace the thermostat with a new one..especially if it's a fresh water motor or in a cold climate.There are products to flush through the motor and remove...desolve salt..
another great video!! :D i just changed the diaphrame on my 40 autolube from 93
Thanks Kristian, good to hear you got your autolube fixed up. :)
Great video after wire wheel. I use a pice of 1/2 inch glass with a sheet of sand paper to make it strait. Figure 8 motion. Have a good one
Yep, that's a great way to ensure the head is still flat.
Nice work Stu! I'll have an outboard spring start video up in the next couple of days. I have a truck video going up tonight!
Thanks Will, I'll be sure to check that video out. I was thinking of doing something a bit similar soon to go with the winterisation video but you beat me to it! ;)
Gearwrench does have ratchet wrenches with reversible drive. I have a few and the head is usually still small enough to get in tight spaces. Little pricey though. Great video as always mate.
I have seen those and they do look very cool. One day!
Awesome video,Keep it up!
Thanks mate!
Thank you for a great video Thanks from Canada
You're welcome Kim. :)
Great and informative are the old 65hp 3cld Mercurys easier to replace the Cooling Head without taking Cylinder head off and having to reseal and replace the cylinder head Gasket.
Nice video but you can tell the guy is backyard trained no factory training of any kind. Which is good down to earth personality not stuck up or tryin to talk a big thumbs up bro!
Thanks Costas, glad you liked it.
Prying usually works, I find tapping around the edges with a brass hammer loosens it up.
Yes, a soft hammer can help... also lossening the hedbolts then cranking the engine... letting the combustion do it for you.
Just became a Patreon- you deserve every penny!
Thanks mate, really appreciate you signing up! :)
Keep up the good work stu, I think it's brilliant that you do this for the public but you gotta put some batteries in your work shop clock 😉
Thanks mate. Battery done! Video out soon. ;)
It's right twice every 24 hours
I changed the headgasket on my Mariner (yamaha engine) 30hp last summer. The gasket was blown and had less than 50% compression than cylinder 1. Snapped two of the headbolts and it was a bitch to fix it. Luckily it was much material left on the cylinder so i could drill the old remains out and make new threads. Now it runs like a champ!
Nice work Mikael, glad to hear you got it fixed up and running nicely again. :)
Master of masters.. I love being ur student
Kiwi tip: if you wind your ratchet spanner out too far...push it in and use a regular set spanner to wind the bolt back in! lol
There are many situations this does not work, simply because the bolt has a flange behind the hex. Your only options then are to cut off the bolt to get your wrench back, or cut the wrench apart to free the bolt. Cutting the bolt is usually the cheaper option, but not always!
Danger, Nice Car Buddy!
Great video. I have a suzuki dt25 1984 and its really hard to start it when cold. When hot engine starts very easy. I am thinking the CDI causes the problem. If that doesnt change the problem i will take a compression test and move onto a head gasket replacement since the outside seems rusted.
In my apprenticeship the instructors always said the torque settings were for 'dry on dry' threads and to never use lubricant on the threads because you will over torque the threads, plus the bolts can vibrate loose easier due to the low friction. Where I work now we use blue Loctite or 'thread sealer' that looks like ATF and sets like a gell and the torque settings are all redone to allow for the fluid being on the threads. Looking at the tables for a 'dry' thread use and a 'sealed' thread use, 12mm bolts with fine threads are roughly 15Nm lower for wet threads, 10mm are 12Nm less, 12mm course thread are 10Nm less and 10mm are 8Nm less. Actually , those are for 'screws' , we don't put thread lock on bolts, we use the sealer on the shank of the bolts and none on the threads, but that is being picky:-) - anti vibration is by spring or star washers.
Hey Ron, I find that a lot of service manuals will specify what conditions their torque settings are under. For example, the Evinrude specified dry but the Yamahas will tell you to add oil so I presume both these stated figures take this in account. As a result oiling the Evinrude will probably give you the wrong result. Interesting point about sealing the thread to stop corrosion getting in there. That sounds like it could save a whole lot of headache down the track!
Sealing the bolts doesn't always work, the holes have to be blind .
The ratchet spanner bit about them getting caught is recoverable if you push the spanner head onto the shank of the bolt and then use a normal spanner to refit the bolt to get clearance back.
but yes - the torque figures in manuals are for the lubricated/not lubricated thread as specified.
Ron Powell your instructor was right. Been working on engine for many years. But you also have to understand it's like cooking. People are taught one way the "basic way" and then over years everyone builds there own way of doing so. But I would say a huge no no on the oil on threads. If you clean the threads like he did then clean the threads in head you need only lock tite to get it rite all the bolts WILL vibrate out the side of the motor especially on a 2 stroke.
thanjs for the video but now i am in the middle of fixing one AND I HAVE TO WAIT for another video so i can fix it, Just kiddingn and really enjoy the videos keep them coming
I'm glad the owner of this boat isn't in a rush either! ;)
On the 2 lower head bolts. You can use a torque wrench with a dog bone wrench at a 90 degree angle and get accurate torque.
Thank you for making this videos are helping me
You're welcome mate.
Wow you make it look easy , i have an 1985 johno 70hp the water jacket was rusted on lol
Yes, sometimes it gets much harder because of bad corrosion.
great videos danger marine! learned alot from your videos. 88 40 hp evinrude running great from you're advise
dangar
Thanks Jason, glad to hear you've got your motor running well. :)
If the cylinder head is stuck you can put back the spark plugs and cranck the engine (leave one or two cylinder head bolts in place but loose)
Yep, I was just mentioning that exact technique to someone else this morning. :)
I heard about it long time ago but fortunately i neved had to use it. Thank you for your time and yor videos.
Nice a new video I've been waiting
Hey Dean, this one was a bit delayed...
Another great vid! Thanks.As to the ratcheting wrench you would like the ones with pivoting heads.Cheers from Canada
what is the effect of wet spark plug air bang engine 9.8
Hi. Great video! As far as I know, there are different tork ratings for dry and for oiled assembly. But I could be wrong.
Thanks mate, some manuals do state specific torque specs for lubricated.
Thanks for the Video, I'm working on changing the cylinder head and head gasket on my 90hp yamaha 2 stroke and ive been having some trouble removing the old gasket material. Ive been using plastic scrapers and a rubber wheel for removing decals off of vehicles that attaches to my drill. I still have some material left and I saw that you used a brass wire wheel for your process so i purchased one and tested on the old cylinder head but it seems to be sratching the surface so i was hoping you could suggest exactly what you used to accomplish this. Thanks in Advance
Wes
Sanding the block with the pistons in is a bad idea, right? I was thinking about doing it with the block still being on the engine in vertical so if anything falls off does it does not get on top of the pistons or deeper into the cylinder.
I have a 15hp yammy that sometimes revs out and mostly won't, this started after replacing a stuck thermostat, it was a $100 motor that seems to have had zero maintenance for its 25 year life, I figured for a $100 it was worth it as I do all my own work. After cleaning carb, and replacing the thermostat I tasted the tips of the sparkplugs and found one was salty indicating water on the plug. It would also occasionally be seized after standing for a day or two but loosened up easily, also indicating water in the cylinder. The strange thing is compression was 125 even on both cylinders. I popped the head off to find the water jacket almost completely blocked, yet the head gasket doesn't look blown. I have ordered a new head gasket and given the cylinders a light deglazing with 320 emery paper on a drill to return some cross-hatching (I have had luck in the past doing this on small 2.5hp tohatsu/mercury's) and hopefully, this will sort the issue. My only hope is that the water is not from a crack somewhere I haven't found yet.
Great video, love this channel !!
Thanks Anders! :)
Great job. Well done
Thank you! Cheers!
Great video your description and explaining is so easy to understand - I’m new to boat engines very familiar to 4 stroke car engines . So you are really helping me to get confident to get a boat and engine and keep it running great 👍 can you recommend a good 100hp outboard and/ or bigger to start my boat life?
You're welcome mate, happy to help. The Yamaha 4 stroke 100s are good outboards.
@@DangarMarine sorry mate I was asking about a good 2 stroke of above 100hp size what’s your professional recommendation 👌?
۸۵ راتوضیح
Nice calendar! Or poster back there... I'm about to pull the cylinder heads off my 1994 200 hp Yamaha. I hope I can get all the bolts out without snapping one off!
Good luck with the job!
Cannot thank you enough for your help
This is a really good video, thx
I like that calendar!!!
Hey Stu,
I am rebuilding an old 15 hp Yamaha, I've replaced cylinder bores, pistons, piston rings and all bearings to the power head.
I can't find information on how to "break in" a "new" outboard (two stroke), maybe you could do a video about that. Or maybe someone who knows will reply to this comment. Thank you.
Cheers
so just for the first 3 gallons use a 25:1 mix (which is simply a pint to 3 gallons). no stabilizer just gas and oil. make sure the throttle is down to a crawl when you first fire it up and just let it idle for the first 10 minutes. don't touch it! let the rings wear in as best they can. then take it out on the water. if you boat is light, smoothly but quickly give it full throttle to plane off, then back off to 1/2 throttle. if the boat is heavy, don't go above 1/2 throttle for the first hour and vary the speed every 5 minutes or so very slightly. if you are out of gas by now, refill with 50:1 for the rest of break in.the second hour you can give it 3/4 throttle every now and again, but continue to vary the speed. from hours 3-10 give it full power every few minutes, but only for 30 seconds or so. BE GENTILE the first 10 hrs. after break in is done, check the plugs and lower unit oil for metal and / or water intrusion. you can now use 100:1 fuel ratio, but be sure to use marine stabilizer each tank for the life of the motor to prevent internal corrosion. its especially important with 100:1 mix as thats not enough oil to protect the crank from corrosion when not in use.
Gday mate good video ,when i did my 50hp triple i changed the sacraficial anodes in the block ,i didnt see any in this 20 do they not put them in smaller engines ? i also cleaned as much of the water jacket on the block as i could with a wire brush on a dremel tool handy piece of kit that anyway 2 strokes as you say are fairly easy to work on
Hi mate. All outboards are a bit different with the location of the internal anodes. Some are under the head, some are accessed from the side of the block. They will all generally have at least one though.
Nice video man!
Thank you! :)
help evinrude 90 hp v4
how tightly to tighten the heads
NM -?
What if you have a spark plug that fires to hot and fouls out with aluminum melted on the plug
Nice video Stu, when changing cylinder head gaskets I usually remove the entire powerhead, take advantage to clean all water paths, decarbon piston heads, exhaust area. Install a new lower base gasket with s slight grease coating at both sides, and torque to specs. that's to be able to remove the powerhead again without harimig the gasket My motor has 4 lower head bolts impossible to be torqued with a torque wrench if powerhead reamins screwed on its base.I'm a manic about torquing all head bolts to same torque spec whichever they are.
Other issue, on 2 strokes 2 cylinder motors have never seen both plugs to come out in same clean cond, the lower one usually comes out bit darker than the upper one, and that's on new out of the box motors with few run hours on them., seems it's the nature of the beast.
When you torque a cylinder gasket with a torque wrench, say needs to be torqued back to 25 NM, you torque it in a single torque straight to 25 NM or in a 2 step process, say 13 on first one, 12 on the second torque adjustment.?
Removing the powerhead would definitely have been better but I'm too lazy. ;)
Have 2 interesting maintenance tips that have been using for several years, does Dangar Marine has an email address to send them over ?
Best way to decarbon piston heads pls? Cheers
Thanks for these fantastic videos. I watch them for hours. Please produce a video or link to how I can reseat the heads on my year 2000 Johnson 115 2-stroke motor. It is leaking slightly at the top inside of the starboard head. It uses sealant rather than a gasket and I need to know the best sealant to use, exactly where and how much to put on. Thanks again.
I don’t own a Johnson 115.
Awesome video
Thanks Brian. :)
This is great, thanks Stu :)
You're welcome Ron, still waiting for that photo!
Hey buddy I just test drove a motor that I traded for some work. 60 evinrude, It's has compression of 90psi,89psi,29psi on bottom cylinder so I've started taking the head of and unfortunately 5 bolts snapped. I was gently as I could pulling them out. Well just the start of a big project. I hope you don't mind me asking questions In future. Anyway beer getting warm trying to get this head off now
By the way trying to get me a shirt funds are tight save a spot on top right of board for me
Hey Bryan, it's pretty common for bolts to snap on old outboards like that, but as you say, it is a big project and one that you will enjoy with the right approach. I'll save a spot for a photo of you with your outboard. :)
Thank you, I am taking a 25 hp Nissan apart due to top head gasket failure, leading to top over heating, loss compression, 85 top and 125 bottom. Top cylinder wall scratched lightly. I wish I could bring both to 120 to 125.
You might find that with a light hone and new rings the compression comes back up. I would also get the head machined before re-installing with a new head gasket.
Thank you so much for the great suggest, yes , l ordered new rings, head gasket, mid sect. gasket and new impeller. All the bearings are still tight and no discolor or burn marks.
How much water should I expect to see coming out of the exhaust ports on an '81 90 hp Evinrude? I replaced the head gaskets thinking that would solve the problem but still getting some water blowing out. It is more of a mist than any kind of flowing water. Everything with the motor seems to be running as it should, no overheating, no fouled spark plugs. Do get some unburnt oil dripping down the lower after trolling for the day which I think is normal.
Would it be a good idea to pack those cylinders with some shop rags to prevent debris from entering while cleaning block?
It certainly wouldn't hurt. I don't worry so much about this crud as I would about metal filings from grinding for example, but its not a bad idea to stuff some rag in there before you start.
Is that a haines signature 1750R in the background mate
Hi Stu, been reaching these head water passage videos again. I'm diving into this for the first time on a 3hp Evinrude 2 stroke. You mentioned the step on having the carb shutters wide open to preform a compression test. I think the reason for this is to rule out defective reed valves. It may affect the readings. I'm new at this internal stuff but thought I would point out the reeds may affect compression?
I have a 1977 Evinrude 25HP and the compression readings I got were 50PSI on the top cylinder and 70PSI on the bottom cylinder..... do you think a leaking head gasket could cause that much of a compression drop or is my problem likely worn piston rings or something "catestrophic" as you put it in the video. If the piston rings are worn I am wondering how do I really tell or if you have a video to diagnose low compression.
Thank you for the videos. Have been watching a lot of them lately while trying to figure out how to get this outboard running. Thank you.
A quick shot of oil in the plug hole and re-do the compression test. A marked rise in figures usually indicate worn rings.
Not a fail safe method, but a pretty good indicator in general.
Around 180 grit wet & dry silicon paper on a wet flat surface (glass) in a figure 8 pattern is preferred ! method, wire buffing a cylinder head not best practice, and make an allowance for possible left over asbestos gasket material on machined surfaces and wire buffing will spread the fibres!
Any chance you got a video tear down rebuild on a tohatsu 50 3cylinder
Stumbled across you channel and learned quite a bit. Have water coming out of my spark plug hole so changed the water jacket gasket without success as there's still water. Pull it all apart and try again. Hope it's not a cracked head. Any other pointers? Thx!
That's not a good sign. It is either gasket or a cracked block or head.
@@DangarMarine Yeah, replaced the head gasket and water jacket and still get water coming out of the lower spark plug hole. Any use dropping the lower unit and replacing the impeller or is the head cracked. I don't see that its cracked. Thanks!
have you done the video on when you break head bolts?
Not yet, but planning to very soon!
If a head bolt feels like it's going to snap off rather than break loose, what is the next step so as not to break or twist the head off the bolt?
@@gmoney2369 Working on old Yamaha dirt bikes back in the 1970's, if a head bolt felt like it wouldn't break free, we would gently heat it with a torch (go easy man - you can warp the head FAST like this if you aren't careful!) and gently tap it several times with a plastic mallet. Spray with WD40, wait a few minutes, tap and spray again, repeat until the bolt has cooled down. Try again. TAKE YOUR TIME.
The heating/cooling cycle expands/contracts the corrosion between the head engine block and bolt holding the head on, and allows the WD40 to penetrate better.
Repeat as many times as necessary... it almost always works, but it sometimes takes many tries. Allow the head/head bolt to COMPLETELY COOL ON IT'S OWN (don't try to cool it down any faster!) before making another attempt!!!
It's better than snapping a Head bolt... ask me how many times I found out. lol
Appreciate the advice. Will give it a try when I finally decide to pull and descale the heads as the last step to deal with overheating issues.
@@gmoney2369
I recently had one break on a 1998 Yamaha C60. It was about 1/8" below flush with the crank case, and I didn't want to risk breaking an EasyOut in it and making things even worse. (they should have called them "Easy-to-Break")
We welded a nut to it, and along with a little heat, and a lot of patience and penetrating oil, it came out.
Hope this helps someone else in that predicament.
Have a 70 Yam. 2 stroke..runs great but overheats at WOT not at slow 6knts. Thermo good. Opened head and saw 2 pieces of the cylinder stiffner broke. It appears they could restrict water in the cooling channels around the cylinders. Ran it without thermo and still over heat and showing 220f on the upper of the 3 cylinders. I'm replacing the head gasket (thanks for this great video) and hope it was the stiffners pieces that caused the restriction. The tell-tale was strong. Think those pieces could have restricted the flow enough to overheat? Thank you
Great video. Very helpful. I learned something today.
Glad it was helpful!
I was surprised after seeing vids of people removing the head like you did and looking at the pistons ect...to realize my 50 merc is a "headless" outboard. Its the strongest stock 50 2 stroke ever made at 59ci(yamaha is like 42) which I'm happy about but I think it sucks I can't remove the head like the other motors. Apparently if I ever want to rebuild this motor I have to find a very knowledgeable machine shop who can bore "blind cylinders". Have you ever had to mess around with a headless outboard before, lol?
I can't say I have worked on. It sounds like it should be quite strong but I guess you need to split the crankcase and pull the pistons out that way if they need and attention. As you say, most machine shops probably don't have much experience with boring them. Fingers crossed it will just keep going!
Thanks You're right im gonna keep it until it dies and keep it well maintained and hope for the best.
Hey Stu great video very helpful i’m currently in the process of replacing the pistons in my 2 stroke yammy you wouldn’t happen to have a video with some tips an tricks on how to do that?
Marine engine don't ship to Sweden yet but when they do I'm gonna order!
They don't ship to Canada either! ^$%*@!!
Would an exhaust leak from head gasket cause air/ exhaust to come out the tell tale? I change the impeller and gasket check the key way for impeller made sure it lined up with water tube that goes up to motor.. if I take the thermostat off and run the engine, water will come out the thermostat housing with some exhaust and out of the tell tale at a good clip for long time.. as soon as I put the thermostat back in I start the engine and water will come out the tell tale for about 20 seconds and then air or exhaust comes out the little pee hole.. don’t know what else to try.. any help would be appreciated.. thanks
Yes, it will cause that. The exhaust will push the water back out of the water jackets causing the engine to overheat, definitely seen that before.
@@DangarMarine thanks for the quick response I have nearly tried everything.. I submerge the lower unit in a 50 gallon drum I took off the thermostat and let it run for 5 minutes.. water was gushing out the thermostat housing and tell tale.. I turned it off put the thermostat housing back on and started it again.. only a good stream from tell tale for about 30 seconds.. as it started heating up the stream kept decreasing until noting but air was pushing out the tell tale… idk what else could be causing this.. has me clueless… thank for ur quick response it’s appreciated.. great videos thank you
@@DangarMarine thanks
I’m having the same problem with an overheating 3hp engine
Stu, I have a Johnson 50 hp. I see some white stuff (salt? corrosion?) around the head gasket near the lower cylinder. Is this the sign that something is wrong or normal occurrence in salt water? Motor starts easy and runs fine. Thanks for the great videos!
Hi Brian, you do see that and it isn't necessarily a sign that the head gasket needs replacing. If you still have good compression I wouldn't worry too much.
I hope my old 30 is going to be great