I'm so grateful for this video! I just confirmed that my 1999 mercury 40 two stroke had indeed sheared its flywheel. In my case the engine would run but only barely and wouldn't throttle up. The boat stays at a remote location where I don't have access to a timing light, so I really don't think I would have figured the problem out myself if I hadn't remembered seeing this video years ago when it came out. Thank you!
I had a 55hp Evinrude that wouldn’t start. I had good compression, a strong spark, and a good flow of fuel. The engine would occasionally back fire but refused to start. Then I came across this video. I checked the locating key and sure enough it had sheared. I fitted a new one and the engine started first time. Thank you so much.
Great tip, really helped me out with a problem that was driving me mad. Been fixing up a Merc 45hp that's been idle for 20 years - got her running after months of work, but then the timing started going all over the place, backfiring, etc. Your video gave me the idea of checking under the flywheel and voila - woodruff had been sheared clean in half! New one in the post, fingers crossed that's all that was wrong. Thanks for all the videos, they are a huge help to total newbies like me!
Thanks for this video. Put my flywheel back on after a new stator, tinier base and power pack and forgot about the key. It was sheared off and was having issues with spark and timing. After a new key, it fired right up. Thanks for saving me a ton of time and money!
Thanks for the videos. Im in Florida and boat has been all around different mechanics plenty of money spent, no one could figure out why no start i pulled the flywheel and boom that was it.
I had a motor mount snap and my engine fell into brackish water. It was during salmon season last year so I bought a new motor and got back to fishing. Long story short, I have been troubleshooting this motor for a month. I bought the same motor and moved the entire fuel system to the old one. Still nothing. Started troubleshooting timing system and discovered the sheared key. Your videos have been super helpful, keep it up!
Sorry I commented on a couple of your other videos. Turns out you've basically got a video for everything. If I put in a bit of effort you've already answered all my questions. I unseized a 115HP outboard. It has good compression. Carbs cleaned up and work well. Good spark. But won't even attempt to fire. I did pop the flywheel nut off and could see the keyway so assumed it was fine. But now I'm going to pull the flywheel. I'm confident this is the answer. Seams obvious now.
@@DangarMarine I built my own puller. First one failed. Was 3mm plate steel and just bent. Secont attempt with 6mm plate worked. The flywheel key was fine. I refitted the flywheel and cranked it. You wouldn't believe it. As I was mucking around with the flywheel I noticed those little notches where you could put in an emergency pull cord. I visualised the pull starting of such a big engine. Then it hit me. The starter motor is turning the wrong way. Someone has welded brackets on to a car starter and mounted it to the outboard. It turns over fine but backwards. I've wasted a good 20+ hours chasing issues. It's good tho because I found splits in some fuel hoses. Flakes blocking the carbs. I'll track dow a genuine starter that turns the correct way and I'm confident it'll fire.
When my brother and I were kids, my dad made us mow the lawn with a little 20" or so push mower in SC heat. We learned that we could push it over an old well pipe and it would shear the flywheel key smooth off! That's how we would get out of work for a while.😁
Thanks for the video Stu. Would you be able to test for a broken key by putting the motor in gear, moving the flywheel by hand, and seeing if the prop spins? Will the flywheel have a lot of slop / play when gently moving left to right?
Love your videos. A quick tip. When something like this happens use some valve lapping compound and spin the flywheel back and forth for a while on the crank. Usually you can save the crank and flywheel having a good tight fit. The key does not hold the flywheel from spinning on the crank. The key is there to time the ignition.
Hello there! Great vid! I got a 99 mariner 90 2s Elpto. Does that one also have a woodruff? I'm just worried I might mess up the timing and I don't know how exactly to mark it correctly. I just need to change my trigger. Thanks!
I think this is my problem on a portable generator. it stopped working and is only spinning and backfiring. Thank you so much for your video. I'm going to try to get to the woodruff key and see. It's not very old and has very few hours on it. Would the intake and exhaust valves be a potential problem?
Great tip, thanks. I'd love to have you include either in your videos or the description what the make, model, hp of engines you are working on, even if the info/tip is relevant to more than just that motor.
are the flywheels pressed on? because i tried starting a grass trimmer 2 stroke engine mounted on a wooden board with a socket and drill i had my finger on the throttle at full throttle when i started it the drill bit socket flew off and the flywheel broke off or came loose the fly wheel is loose but stuck on the shaft because i have a nut on the shaft i dont know what to do
Novice question....If you were to just resleeve the fly wheel, how can you guarantee that the timing won't be out (by 1 to 2 degrees or so). My thinking being that only one side of the keyway is going to have been worn out under load. Or is there enough timing adjustment in the motor to compensate?
Hey Mark, that's a really good question. I am presuming that the sleeve would also be keyed somehow to the flywheel but I'll look into it and post a video when I do the job.
Great video! Learning so much from watching you. Where do you source your service manuals? We have taken on a 40 year old Mercury 70HP outboard and want to get it operational and then service it, problem is I can't find the correct service manual for it anywhere! Any suggestions?
Can uou help.... small two stroke engine (Chinese), fly wheel has spun due not to the key shearing but rather the centre of flywheel is machined steel caste into the flywheel without anything to hold to key it into the caste... pretty stupid as this flywheel drives the post hole digger... my task is to drill and tap three bolts through the caste into the centre machined section to stop further slipping of the outer flywheel... My question is How do I position the magnets so that timing is acceptable as there is no way to tell original position..... Thankyou Wayne K
Nice video! Do you think my flywheel could be bad? I was on the lake bogged down but made it to shore by giving and letting go of throttle, when I opened it the flywheel cover was half open and a bunch of oil in my hull, now wont start and backfires. Got it on once on land after the bog down but that was it and it died down when I let go of throttle.
Re: 1996 Evinrude V6 - 60 deg 150 hp. What causes fragments and chips in a flywheel? Could chips cause loss of magnet strength and result in reduction in magnetic force, and ultimately voltage? After replacement of plugs, wires, coils, and power pack (all ORM Parts) engine would not still run. After replacing optic sensor, engine fired and eventually started, but barely will run (VERY erratic), and only runs for a minute or two. Btw, I’m guessing; fragments may have caused failure of optic sensor. That said, could flywheel be the issue? Thanks for all your great videos and never-ending help. Like it or not, you’re like a buddy that stops-by occasionally to help wrench on a few bolts over a beer or two. Thanks again.
You have described exactly my problem with a Tohatsu 5hp two-stroke. It was stuck and while forcing it the flywheel must have slipped. Only problem is it will not come off despite using the special tool, wd40 etc. Only thing I have not tried is heating it but I'm afraid of damaging what's underneath. It seems really glued!!!
I am rebuilding a 1986 mercury 50hp that has been sunk. I believe I know what I need to know, except I know nothing about timing. Will I need to time it other than on the linkage if the woodruf key is ok?. Its been completely tore down, cylinders removes and all..
Hi Stu, I think this is your first name by other responses. pardon me if I'm wrong. anyway the engine in this video looks like my 1996 60 horse 2 stoke 3 cylinder mercury outbd and have a question. I have the process down for checking my static timing and no problem on the idle timing but the Seloc manual shows max cranking at 24 degrees BTDC and WOT at 22 degrees BTDC. Which one should I go by? I know whatever it shows without the plugs installed set it 2 degrees lowered since there is load on the engine. just want to have it right. I know to high of timing can damage the pistons. thanks
Hi mate, yes Stu is right. If there is any confusion I would always go with the lower number (22 BTDC). If the timing is too advanced you can do damage, if it is slightly retarded you will only lose a small amount of power.
Dangar Marine OK thanks Stu, I'll go with the lower one which is the max cranking setting at 22 degrees. but will lower it to 20 since the plugs not in when checking the timing. power is not that major of an issue for me.
think I figured out the problem on my ebike hub motor thanks in part to videos like yours. so, my motor would spin and the wheel would turn ONLY if was off the ground and there wasn’t a load on my ebike seat (me sitting on it). It was a strange problem because Hall Sensors work properly and the motor phase wires are good. The problem is/was when I open the motor I guess somehow I lost/misplaced the key stock/woodruff key. didn’t realize how important this lil guy is. learned that without it planetary gears won’t stay aligned properly to generate enough force to push ebike forward and wheel will only spin without a load on ebike. ordered replacement part (pack) on Amazon. Does this sound about right? Great video, btw. /Bklyn👑
Question, even with a bad key, will you be able to start it with a spray of starting fluid in carb? Or if you have a bad key, it will not fire up at all. Im starting to wonder....i might have a sheared off key. I did everything else, new plugs, cleaned carb 200 times, battery good, compression test, starter...ect...
I have the opposite problem. Mine sheared the key but also took half the crankshaft groove off. Basically it won’t hold the key anymore. Do I tap it for threads and use a set screw?
This has happened on my 25hp mercury. One question... Why would the scoring on the inside of the flywheel (like you show at 2:40) cause an issue? Mine looks just like that.
Your reply is up a while, I hope you’re fixed up now. The flywheel is driven by friction between the taper surfaces rather than the key. Because the shaft is trying to accelerate and decelerate throughout the combustion cycle, this joint is always working hard and a key cannot take the force. If the surfaces cannot touch intimately because of roughness and effectively seize, flywheels will move. A small amount of damage can be checked and repaired by blueing and lapping in. Otherwise it’s an expensive machine shop job or full replacement. There must be no possibility of rocking on the shaft, before tightening the lock nut. I’ve had some success with loctite when a proper repair was uneconomical desperate. Incidentally Dangar’s tip to stick the key with a dab of grease is dodgy. The taper area should be spotlessly clean of grease. Use a tiny punch mark or a small bit of thread lock to retain a loose key. I like to lube the nut and tighten by feel. Otherwise follow the manual, usually dry thread and torque wrench.
I sadly somehow broke the magnet portion (center timing magnets) off the flywheel and want to know if that needs to be replaced or if it could be epoxied back on, similar problem to the flywheel key knocking loose but what would you do in that situation? It's from a 70HP 2 stroke evinrude motor.
That's a good question. I've certainly seen some broken magnets continue to work just fine so if it was me I would try glueing it and seeing how it goes. You can always replace it if it doesn't run / charge correctly.
Have a quick question that maybe you can answer. My Outboard had a sheared flywheel key. Changed the key, Changed plugs and will still backfire when I try to start. Motor is a 1970 Johnson 60hp. Last checked had 150 compression on all cylinders and getting good spark. Any thoughts???
They plug wires are cut to length from the timer base so I don’t think I can mis wire them. Motor was running but missing a bit when the key sheared and stalled out. Could it just be that it flooded and backfiring out of exhaust? Don’t see any way to install flywheel or stater/timerbase incorrectly to mess of timing. Is the initial timing just set up by lining the flywheel and crankshaft via the key? Thanks for the response!
Dangar Marine I actually think it was just flooded. Floats weren’t set correctly so it was flooding and it just so happened that the fly wheel key sheared the same time.... I let it sit overnight with the carburetors open and reconnected everything. Sprayed some starter fluid in and it fired right up, Reved up high and smoked a bit and then settled into a decent idle. Still feel like my timing or plug leads need attending to.
Stu, have you heard of "Lapping" the flywheel to the shaft? I've watched a couple of UA-cam videos on it (go cart or ATV engines) what are your thoughts on it?
Dangar Marine, I ended up doing the process. It made the two surfaces joint nicely. The flywheel was a little rough when I began but smoothed it out after a good minute plus of rotating. I'm glad that I did it.
Man.. Had my 15hp motor running in the lake and it died.. Took it home and opened the flywheel and saw this woodruff magneticed to the inside wall.. And damaged some things. Fingers cross it still works.. No idea how that happened... Only clue was that the fly wheel was not tight. Hammered it back in.. Dont look like it will go anywhere now.. But you never know do to vibration. What would of caused this?
I use a over size one sanded down..wood drift key that is but now have up and down movement in crank..Johnson 9.9 1980 is it going to kill it or normal for that make?
Is it the crank moving up and down or the flywheel on the crank? I've certainly seen some cranks move up and down a bit on the main bearings without any serious effect.
Actually, I would think that a machine shop could machine a key that was the right size for both original crankshaft slot, AND the larger flywheel slot. This "should" work fine, as offset keys in camshafts and cranks on other engines (not sure about outboards) to change the timing for special uses has been done for many, many years. At least since the 60's that I know of. LOTS cheaper than even a repaired flywheel, yes? RichE
My motor still running fine ,just has a lot a play in crank bearings..I be a believer don't fix what's not broken..I intend to build my 8 HP Yamaha that needs every thing but power head and foot..It's a victim of fire and thief.Then the 9.9 will be a back up motor.
hey i have a question.if the tip of the crank shaft is stripped and i do not have a big enough die for the re-threading what would you do? im out of options here i dont know how it got stripped maybe from the starter pawls when they broke im not to sure any ideas?
Dangar Marine - hey that might take awhile to get to me and by that time the summer will be over. lol. Ihave used a pitch to the top bolt of the crank shaft and it is 18 SAE and then the width is about .90. so i've consulted many mechanics but none are to specific in my area as we have a mechanic that flies in from time to time, i have found a thread file restorer and it had the right size pitch of 18 so that may be my best bet. I wish there were mechanics like you around in my area lol great work keep it up
I bought a used motor that wasn't running. Spent a few weeks trying to get it running. Pulled the flywheel off and the key was lying at the bottom on the coil plate.
I have a 88hp Evinrude outboard the key was sheared off and it's been replaced now motor won't start it has good compression and it has spark carbs have fuel but start it will kick out some smoke. I pulled plugs and fuel is getting to the cylinders any help would be appreciated also it's been sitting for 5 years or so
If it has fuel getting into the cylinders, good spark and compression it can really only be timing that is causing it not to run. Put a timing light on it and see what it is at.
Yup! Or both to keep the bushings from wearing out prematurely. And on small engines (84 Evinrude 15hp), most shops won't even try to replace the bushing as they find the prop hub cracks, or want as much as a replacement. Fortunately, there are now props for even this small motor with user replaceable hubs! And even more fortunately (after the misfortune of my previous 15hp overheating and now having NO compression), the prop on that was still good and fits the replacement motor... :) Thanks again. RichE
Thomas Flynn This POS goes on EVERY ouboard video begging for help to fix a motor that he can't even diagnosis! I mean BASIC stuff. He is Forest Gumps grandpappy! Then has an attitude when people don't rush to help him fix what he probably messed up. He couldn't tell his peepee from his stank hole unless a youtube viedo explained it in SSLLLLLOOOOWWWWWWW motion
the flywheel must stuck on the top of the crankshaft "khonus" part, otherwise it will "play-out-self" again, and ruin the key... again it's a more serious problem as it is looks at first glance i think, especially with that BIG engine:/ the screw on the top is just the Half part of the "Holding it on" snug i hope it will last long!
thanks again Stuart thanks to you I am slowly restoring my boat I must send you some pic over here you go i205.photobucket.com/albums/bb49/anthony300l/20161013_194656.jpg
I'm so grateful for this video! I just confirmed that my 1999 mercury 40 two stroke had indeed sheared its flywheel. In my case the engine would run but only barely and wouldn't throttle up. The boat stays at a remote location where I don't have access to a timing light, so I really don't think I would have figured the problem out myself if I hadn't remembered seeing this video years ago when it came out. Thank you!
I had a 55hp Evinrude that wouldn’t start. I had good compression, a strong spark, and a good flow of fuel. The engine would occasionally back fire but refused to start. Then I came across this video. I checked the locating key and sure enough it had sheared. I fitted a new one and the engine started first time. Thank you so much.
You're welcome Kev, glad you found the problem.
Wow thank you we got our 1973 20hp jonhson engine working perfectly because of this video
Great tip, really helped me out with a problem that was driving me mad. Been fixing up a Merc 45hp that's been idle for 20 years - got her running after months of work, but then the timing started going all over the place, backfiring, etc. Your video gave me the idea of checking under the flywheel and voila - woodruff had been sheared clean in half! New one in the post, fingers crossed that's all that was wrong. Thanks for all the videos, they are a huge help to total newbies like me!
Glad you found the problem mate!
Thanks for this video. Put my flywheel back on after a new stator, tinier base and power pack and forgot about the key. It was sheared off and was having issues with spark and timing. After a new key, it fired right up. Thanks for saving me a ton of time and money!
Same. Thanks!!!
This video saved me big time, the only one found showing exactly how to fix my problem on my own. Thank so much!!
Same here this guy is amazing
From one outboard hobby mechanic you make great informative videos.
Thanks for the videos. Im in Florida and boat has been all around different mechanics plenty of money spent, no one could figure out why no start i pulled the flywheel and boom that was it.
I had a motor mount snap and my engine fell into brackish water. It was during salmon season last year so I bought a new motor and got back to fishing. Long story short, I have been troubleshooting this motor for a month. I bought the same motor and moved the entire fuel system to the old one. Still nothing. Started troubleshooting timing system and discovered the sheared key. Your videos have been super helpful, keep it up!
Glad you found the problem in the end!
Great tip, mate. Completely helped me sort out the same problem I had with a motorcycle engine. Top marks!
Sorry I commented on a couple of your other videos. Turns out you've basically got a video for everything. If I put in a bit of effort you've already answered all my questions. I unseized a 115HP outboard. It has good compression. Carbs cleaned up and work well. Good spark. But won't even attempt to fire. I did pop the flywheel nut off and could see the keyway so assumed it was fine. But now I'm going to pull the flywheel. I'm confident this is the answer. Seams obvious now.
It's a tricky problem to diagnose so if everything else looks good it may well be your problem. Good luck!
@@DangarMarine I built my own puller. First one failed. Was 3mm plate steel and just bent. Secont attempt with 6mm plate worked. The flywheel key was fine. I refitted the flywheel and cranked it. You wouldn't believe it. As I was mucking around with the flywheel I noticed those little notches where you could put in an emergency pull cord. I visualised the pull starting of such a big engine. Then it hit me. The starter motor is turning the wrong way. Someone has welded brackets on to a car starter and mounted it to the outboard. It turns over fine but backwards. I've wasted a good 20+ hours chasing issues. It's good tho because I found splits in some fuel hoses. Flakes blocking the carbs. I'll track dow a genuine starter that turns the correct way and I'm confident it'll fire.
When my brother and I were kids, my dad made us mow the lawn with a little 20" or so push mower in SC heat. We learned that we could push it over an old well pipe and it would shear the flywheel key smooth off! That's how we would get out of work for a while.😁
Yeah found this video just after finding my old evinrude had suffered this same fault. Good to know for future. Keep up the good work.
Wow... Thanks for your videos... I fixed my boat motor that has not run in two years... It to was the flywheel key...
Glad to hear you got it going again. It can be a tricky one to track down if you don't know the symptoms as it is so out of view.
Dangar Marine I have bad motor when you check me for it
Thanks for the video Stu. Would you be able to test for a broken key by putting the motor in gear, moving the flywheel by hand, and seeing if the prop spins? Will the flywheel have a lot of slop / play when gently moving left to right?
This video helped a lot. I would have thought to check this.
Thank you.
Great video, thanks. You make it all look so easy
Thanks mate.
Love your videos. A quick tip. When something like this happens use some valve lapping compound and spin the flywheel back and forth for a while on the crank. Usually you can save the crank and flywheel having a good tight fit. The key does not hold the flywheel from spinning on the crank. The key is there to time the ignition.
Nice idea to lap the fit to make it tight again. :)
How is removing material from 2 parts going to make it tight again?It looks like it would make it l ooser
Hello there! Great vid! I got a 99 mariner 90 2s Elpto. Does that one also have a woodruff? I'm just worried I might mess up the timing and I don't know how exactly to mark it correctly. I just need to change my trigger. Thanks!
I think this is my problem on a portable generator. it stopped working and is only spinning and backfiring. Thank you so much for your video. I'm going to try to get to the woodruff key and see. It's not very old and has very few hours on it. Would the intake and exhaust valves be a potential problem?
Backfiring is more likely to be a timing issue like this.
You just solved my issue!!! Thank you. Replaced the stator forgot to put the key back and bam no start. 🤦🏻♂️.
it brings out the inner sportsman in you.
Excellent video. That would be really easy to miss if you aren't familiar with how they work.
Thanks Seth. For sure this is one that could leave you scratching your head.
Love your videos !
Great tip, thanks. I'd love to have you include either in your videos or the description what the make, model, hp of engines you are working on, even if the info/tip is relevant to more than just that motor.
Thanks mate, good point about mentioning models. This one was a 60hp Mariner but I'd have to check the year.
Wow, I've never seen that happen. Great tip, thanks for the video.
It's not common, but it's worth keeping in mind if you ever have a no start when everything else seems fine.
are the flywheels pressed on?
because i tried starting a grass trimmer 2 stroke engine mounted on a wooden board with a socket and drill
i had my finger on the throttle at full throttle when i started it
the drill bit socket flew off and the flywheel broke off or came loose
the fly wheel is loose but stuck on the shaft because i have a nut on the shaft
i dont know what to do
Novice question....If you were to just resleeve the fly wheel, how can you guarantee that the timing won't be out (by 1 to 2 degrees or so). My thinking being that only one side of the keyway is going to have been worn out under load. Or is there enough timing adjustment in the motor to compensate?
Hey Mark, that's a really good question. I am presuming that the sleeve would also be keyed somehow to the flywheel but I'll look into it and post a video when I do the job.
Great video! Learning so much from watching you. Where do you source your service manuals? We have taken on a 40 year old Mercury 70HP outboard and want to get it operational and then service it, problem is I can't find the correct service manual for it anywhere! Any suggestions?
Can uou help.... small two stroke engine (Chinese), fly wheel has spun due not to the key shearing but rather the centre of flywheel is machined steel caste into the flywheel without anything to hold to key it into the caste... pretty stupid as this flywheel drives the post hole digger... my task is to drill and tap three bolts through the caste into the centre machined section to stop further slipping of the outer flywheel... My question is How do I position the magnets so that timing is acceptable as there is no way to tell original position..... Thankyou Wayne K
Another great tip. Thanks Stu
You're welcome Kevin. :)
Nice video! Do you think my flywheel could be bad? I was on the lake bogged down but made it to shore by giving and letting go of throttle, when I opened it the flywheel cover was half open and a bunch of oil in my hull, now wont start and backfires. Got it on once on land after the bog down but that was it and it died down when I let go of throttle.
Thank you Sir. That engine looks like the one Im working on, a 1996 Suzuki V6 200
You're welcome. This motor was an old 60 HP Mariner.
Re: 1996 Evinrude V6 - 60 deg 150 hp. What causes fragments and chips in a flywheel? Could chips cause loss of magnet strength and result in reduction in magnetic force, and ultimately voltage? After replacement of plugs, wires, coils, and power pack (all ORM Parts) engine would not still run. After replacing optic sensor, engine fired and eventually started, but barely will run (VERY erratic), and only runs for a minute or two. Btw, I’m guessing; fragments may have caused failure of optic sensor. That said, could flywheel be the issue?
Thanks for all your great videos and never-ending help. Like it or not, you’re like a buddy that stops-by occasionally to help wrench on a few bolts over a beer or two. Thanks again.
You have described exactly my problem with a Tohatsu 5hp two-stroke. It was stuck and while forcing it the flywheel must have slipped. Only problem is it will not come off despite using the special tool, wd40 etc. Only thing I have not tried is heating it but I'm afraid of damaging what's underneath. It seems really glued!!!
Prybar with upwards force under the flywheel and rubber or metal mallet hitting the crankshaft hard. It will pop off
Your videos are brilliant have this exact same problem 👌 I subscribed watching from Ireland 🇮🇪
can you tell me the symptoms of a pulser coil problem on a 40 HP 2 stroke engine
Great tip Stu!
Thanks Will.
I am rebuilding a 1986 mercury 50hp that has been sunk. I believe I know what I need to know, except I know nothing about timing. Will I need to time it other than on the linkage if the woodruf key is ok?. Its been completely tore down, cylinders removes and all..
I just want to thank you for all your videos, they have been very helpful on repairing my outboard. Keep up the great work! 🤙🏽
Thanks Omero, glad you've been enjoying the vids. :)
if that key is broken would the flyweel will turn easy or not
Thank you for your tip ! Brilliant 👍
Is there a procedure to test the strength (weakness) of individual magnets in the flywheel?
Love your videos. Very informative.
Thanks mate, glad you are enjoying them. :)
Hi Stu, I think this is your first name by other responses. pardon me if I'm wrong. anyway the engine in this video looks like my 1996 60 horse 2 stoke 3 cylinder mercury outbd and have a question. I have the process down for checking my static timing and no problem on the idle timing but the Seloc manual shows max cranking at 24 degrees BTDC and WOT at 22 degrees BTDC. Which one should I go by? I know whatever it shows without the plugs installed set it 2 degrees lowered since there is load on the engine. just want to have it right. I know to high of timing can damage the pistons. thanks
Hi mate, yes Stu is right. If there is any confusion I would always go with the lower number (22 BTDC). If the timing is too advanced you can do damage, if it is slightly retarded you will only lose a small amount of power.
Dangar Marine OK thanks Stu, I'll go with the lower one which is the max cranking setting at 22 degrees. but will lower it to 20 since the plugs not in when checking the timing. power is not that major of an issue for me.
After installing a new key after running it continues to sheer the key. Why
"Can be really frustrating to diagnose" yes I agree.
think I figured out the problem on my ebike hub motor thanks in part to videos like yours.
so, my motor would spin and the wheel would turn ONLY if was off the ground and there wasn’t a load on my ebike seat (me sitting on it).
It was a strange problem because Hall Sensors work properly and the motor phase wires are good.
The problem is/was when I open the motor I guess somehow I lost/misplaced the key stock/woodruff key.
didn’t realize how important this lil guy is. learned that without it planetary gears won’t stay aligned properly to generate enough force to push ebike forward and wheel will only spin without a load on ebike.
ordered replacement part (pack) on Amazon.
Does this sound about right? Great video, btw.
/Bklyn👑
Question, even with a bad key, will you be able to start it with a spray of starting fluid in carb? Or if you have a bad key, it will not fire up at all. Im starting to wonder....i might have a sheared off key. I did everything else, new plugs, cleaned carb 200 times, battery good, compression test, starter...ect...
No, once the the flywheel has slipped the spark timing is way off and it won't run at all.
love your videos, they are very educational. I am learning a ton. Big thanks :-)
Thanks Jimmy, you're most welcome. :)
I have the opposite problem. Mine sheared the key but also took half the crankshaft groove off. Basically it won’t hold the key anymore. Do I tap it for threads and use a set screw?
You could for sure. Anything to stop it rotating on the shaft will work.
Did you end up tapping threads for a set screw into the crank? Or the flywheel?
Is this a Mariner 50?
This has happened on my 25hp mercury. One question... Why would the scoring on the inside of the flywheel (like you show at 2:40) cause an issue? Mine looks just like that.
Your reply is up a while, I hope you’re fixed up now. The flywheel is driven by friction between the taper surfaces rather than the key. Because the shaft is trying to accelerate and decelerate throughout the combustion cycle, this joint is always working hard and a key cannot take the force. If the surfaces cannot touch intimately because of roughness and effectively seize, flywheels will move. A small amount of damage can be checked and repaired by blueing and lapping in. Otherwise it’s an expensive machine shop job or full replacement. There must be no possibility of rocking on the shaft, before tightening the lock nut. I’ve had some success with loctite when a proper repair was uneconomical desperate.
Incidentally Dangar’s tip to stick the key with a dab of grease is dodgy. The taper area should be spotlessly clean of grease. Use a tiny punch mark or a small bit of thread lock to retain a loose key.
I like to lube the nut and tighten by feel. Otherwise follow the manual, usually dry thread and torque wrench.
@@jimwoods9551 Thanks for replying! I was able to fix my motor and it runs great now. Things must be snug enough to keep it going strong!
another good tip cheers stu
Thanks Steve!
Great video, so I need to replace that sleeve in the center of the flywheel. How do I go about doing that and finding that part?
Unfortunately you can often only buy the whole flywheel.
I had this problem on my Yamaha 40hp
Hey Eric, it might not be common, but it certainly does happen!
Would removing the flywheel via the 8 bolts on top cause this?
I sadly somehow broke the magnet portion (center timing magnets) off the flywheel and want to know if that needs to be replaced or if it could be epoxied back on, similar problem to the flywheel key knocking loose but what would you do in that situation? It's from a 70HP 2 stroke evinrude motor.
That's a good question. I've certainly seen some broken magnets continue to work just fine so if it was me I would try glueing it and seeing how it goes. You can always replace it if it doesn't run / charge correctly.
Have a quick question that maybe you can answer. My Outboard had a sheared flywheel key. Changed the key, Changed plugs and will still backfire when I try to start. Motor is a 1970 Johnson 60hp. Last checked had 150 compression on all cylinders and getting good spark. Any thoughts???
Are the spark plug leads connected to the correct cylinders?
They plug wires are cut to length from the timer base so I don’t think I can mis wire them. Motor was running but missing a bit when the key sheared and stalled out. Could it just be that it flooded and backfiring out of exhaust? Don’t see any way to install flywheel or stater/timerbase incorrectly to mess of timing. Is the initial timing just set up by lining the flywheel and crankshaft via the key? Thanks for the response!
Dangar Marine I actually think it was just flooded. Floats weren’t set correctly so it was flooding and it just so happened that the fly wheel key sheared the same time.... I let it sit overnight with the carburetors open and reconnected everything. Sprayed some starter fluid in and it fired right up, Reved up high and smoked a bit and then settled into a decent idle. Still feel like my timing or plug leads need attending to.
My evinrude 115 etec 2007 does not have one, cant fint one even in the manual 🧐
You are best, i like your things....
Thank you, glad you enjoy. :)
Awesome 👍
I have newly purchased a 25 Hp mercury Obm 2 stroke and after installed and start some time After engine stopped and fly wheel jammed why the reason
Has the whole engine seized?
Stu, have you heard of "Lapping" the flywheel to the shaft? I've watched a couple of UA-cam videos on it (go cart or ATV engines) what are your thoughts on it?
Can't say I've ever heard of it, but it's interesting to hear you mention it. I'll do a bit of research. Certainly never seen it done on an outboard.
Dangar Marine, I ended up doing the process. It made the two surfaces joint nicely. The flywheel was a little rough when I began but smoothed it out after a good minute plus of rotating. I'm glad that I did it.
Thanks a lot
You're welcome. :)
Man.. Had my 15hp motor running in the lake and it died.. Took it home and opened the flywheel and saw this woodruff magneticed to the inside wall.. And damaged some things. Fingers cross it still works.. No idea how that happened... Only clue was that the fly wheel was not tight.
Hammered it back in.. Dont look like it will go anywhere now.. But you never know do to vibration. What would of caused this?
It's weird that it came right out. Maybe it had always been that way since the last installation???
I use a over size one sanded down..wood drift key that is but now have up and down movement in crank..Johnson 9.9 1980 is it going to kill it or normal for that make?
Is it the crank moving up and down or the flywheel on the crank? I've certainly seen some cranks move up and down a bit on the main bearings without any serious effect.
Actually, I would think that a machine shop could machine a key that was the right size for both original crankshaft slot, AND the larger flywheel slot. This "should" work fine, as offset keys in camshafts and cranks on other engines (not sure about outboards) to change the timing for special uses has been done for many, many years. At least since the 60's that I know of.
LOTS cheaper than even a repaired flywheel, yes?
RichE
My motor still running fine ,just has a lot a play in crank bearings..I be a believer don't fix what's not broken..I intend to build my 8 HP Yamaha that needs every thing but power head and foot..It's a victim of fire and thief.Then the 9.9 will be a back up motor.
hey i have a question.if the tip of the crank shaft is stripped and i do not have a big enough die for the re-threading what would you do? im out of options here i dont know how it got stripped maybe from the starter pawls when they broke im not to sure any ideas?
Looking online it seems that you can buy individual dies up to quite large sizes, eg. www.ebay.com.au/i/122542985650?chn=ps&dispItem=1
what size die would i need?
Dangar Marine - hey that might take awhile to get to me and by that time the summer will be over. lol. Ihave used a pitch to the top bolt of the crank shaft and it is 18 SAE and then the width is about .90. so i've consulted many mechanics but none are to specific in my area as we have a mechanic that flies in from time to time, i have found a thread file restorer and it had the right size pitch of 18 so that may be my best bet. I wish there were mechanics like you around in my area lol great work keep it up
I bought a used motor that wasn't running. Spent a few weeks trying to get it running. Pulled the flywheel off and the key was lying at the bottom on the coil plate.
That'll do it. ;)
I have a 88hp Evinrude outboard the key was sheared off and it's been replaced now motor won't start it has good compression and it has spark carbs have fuel but start it will kick out some smoke. I pulled plugs and fuel is getting to the cylinders any help would be appreciated also it's been sitting for 5 years or so
If it has fuel getting into the cylinders, good spark and compression it can really only be timing that is causing it not to run. Put a timing light on it and see what it is at.
Dangar Marine thank you for the input do you know of an online resource for the correct timing and linkage location to put it back to stock
❤❤❤❤ thanks dear
Love your videos, very informative, by the way my 70s vintage merc 115 hp 2 stroke "tower of power" uses a timing belt driving the distributor.
Hey Chuck, interesting setup. A guess this woodruff key failing is very much like the belt slipping on your outboard.
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The woodruff key did exactly what it was supposed to do, it sheared off to prevent further damage to the seized motor.
Indeed. I wish props still had shear pins instead of these rubber bushings. So much more servicable.
Yup! Or both to keep the bushings from wearing out prematurely. And on small engines (84 Evinrude 15hp), most shops won't even try to replace the bushing as they find the prop hub cracks, or want as much as a replacement. Fortunately, there are now props for even this small motor with user replaceable hubs! And even more fortunately (after the misfortune of my previous 15hp overheating and now having NO compression), the prop on that was still good and fits the replacement motor... :)
Thanks again.
RichE
what year is that? Made in Korea?
Good question, I'm guessing about mid 1990s maybe.
out sourdeing fo cheap labor!
your country do that?
Thomas Flynn You are a f ing moron dip sh!+
Thomas Flynn This POS goes on EVERY ouboard video begging for help to fix a motor that he can't even diagnosis! I mean BASIC stuff. He is Forest Gumps grandpappy! Then has an attitude when people don't rush to help him fix what he probably messed up. He couldn't tell his peepee from his stank hole unless a youtube viedo explained it in SSLLLLLOOOOWWWWWWW motion
good to know thanks..
Welcome. :)
the flywheel must stuck on the top of the crankshaft "khonus" part, otherwise it will "play-out-self" again, and ruin the key... again
it's a more serious problem as it is looks at first glance i think, especially with that BIG engine:/
the screw on the top is just the Half part of the "Holding it on" snug
i hope it will last long!
The flywheel will definitely need to be repaired or replaced before this can go back on the water.
I'll be very interested in what is done, repair, new bushing(?), or needs replacement ($$$!, I imagine).
Thanks for another great video.
RichE
I wish I had this earlier
There are so many video I wish I had made earlier!
I wish I was younger.... :)
RichE
yeah another great video,but what do you know about fishing? lol, Regards Stu.
I know I enjoy it! :)
crank
thanks again Stuart thanks to you I am slowly restoring my boat I must send you some pic over here you go i205.photobucket.com/albums/bb49/anthony300l/20161013_194656.jpg
Thanks Anothony. You're boat is looking great and I love the name. ;)
What is the boat and year?