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Help identifying noise emanating from underneath fly wheel.

M

mitchbuck

Contributing Member
I had a newer used powerhead professionally installed on a 2003 Honda 50hp Outboard last year and the engine worked great (if you have been following my other threads this is not the engine with bad pee stream). I have been getting the boat ready this year and taken it on several shakedown cruises when I noticed that there is an odd sound coming from what sounds like underneath the fly wheel. The engine works fine but it sounds like something is loose and shaking or scrapping underneath the fly wheel. I reached up under the fly wheel and the coils feel tight. I am wondering if maybe a fly wheel magnet or hardware for the coils could be loose? Or if it could be just the sound emanating from underneath the fly wheel, but the problem is deeper in the engine? I made this short video and let me know what you think.

My plan as of right now is to pop the fly wheel this week and take a look. I actually have a spare from a parts engine that is in good shape that I can replace it with if the fly wheel magnets are coming apart.
 
I have heard og coils delamating somewhere on this forum before.
Please remember to keep fingers and shirt sleeves well away from rotating parts, its a sure way to loose an arm.
You are lucky having spares. My plan would also be to have a look under the fly wheel.
Good luck.
Dean.
 
The BF40/45/50 are known for the flywheel magnets to delaminate and contact the coils making a ticking noise which increases with engine speed.
If that is your problem there will be obvious signs once you have removed the flywheel.
Bob
 
Update. So I popped the fly wheel this afternoon and the magnets and inside of the fly wheel look like that they're in great condition as you can see in the first photo. Much better than the spares that I have. However, I discovered that one of the coils is delaminating as can be seen in the second photo! The exposed coil pack looks to be in great condition though, and I am wonder if there is some kind of tape or fiberglass cloth or something? I don't think that the delamination was caused by loose magnets because it would have abraded the outside of the coil packs, which is not abraded. What do you guys think? Also, does any one know the torque specs for the bolts on the fly wheel of a BF50A? Trying to find them in the Seloc manual but its such a poor piece of literature.
UnderFlyWheel.jpgCoils.jpg
 
Fiberglass sounds like a great idea. My Honda workshop manual says47.7ft-lb. 66Nm for the 4 flywheel bolts.
 
Thanks for the input. So I swapped in a used pair of coils from a parts engine I have for testing and then lightly oiled the tensioner. The noise remained. Anyways, so I decided to run the boat this weekend and both engines ran great for two days in a row. So Not really sure where to go from here. I think I'll just monitor it unless anyone else has any good ideas....
 
If the cambelt tensioner bearing is the cause of the noise e.g. the bearing is worn out or rusted inside, oiling it will not make it quieter, it must be renewed.

Bob
 
Thanks. It "sounds" like the noise is coming from underneath the fly wheel and not the tensioner, but maybe the sound is traveling. I'm going to keep an eye on it. The tensioner looks in great condition with no signs of corrosion.
 
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