Causes of Mid-Section Squeals/Squeaks?

[MotorlessCSJ16]

I've made numerous posts and no-one has helped me yet.

I hate to clutter the forum but I know it has a good reputation of having numerous very knowledgeable people.

Anyway I have a squeak/squeal that occurs when I come off WOT runs and lasts for a while until dwindling away. It sounds as if it's coming from the mid-section or possibly lower unit and I'm 95% sure it's not from the powerhead.

The motor runs great at all RPM (although I run decently rich at idle so it's a little rough).

I've heard bearing failure and what-not are possibilities but what are some tell-tale signs of a bearing failure? Does this issue even seem like it could be a bearing?

The motor is a 1998 Mercury 25hp tiller.

Any help would be greatly appreciated.

 

[MotorlessCSJ16]

Re: Causes of Mid-Section Squeals/Squeaks?

Bump

 

[Jay101379]

Re: Causes of Mid-Section Squeals/Squeaks?

Greetings...I've got the same problem you describe with my 1995 75 hp. Merc. If you run WOT for a while then back off to an idle it sounds almost like a fan belt squeaking under the cover. It does it for maybe 2-3 minutes then slowly fades away. I run it in salt water and I do flush it regularly. Did you ever figure out what the issue was with yours? Thank you.

 

[woody66912]

Re: Causes of Mid-Section Squeals/Squeaks?

Motor, if this is 4 stroke, it will be the base gasket. There was a service bulletin on this. the exhaust back compression caused the metal base gasket to make a squealing noise, the fix for this was to pull the power head and drill a 3/8s relief hole in the back port side of of the gasket. The area to drill was roughly
3'' by 4''. And yes you can reuse gasket.

 

[Jay101379]

Re: Causes of Mid-Section Squeals/Squeaks?

My 75 hp. is a 1994 2 stroke...a bearing issue would make sense, regardless it's definitely something creating friction that's making the noise. I'm hoping someone will chime in who's experienced the issue and found a solution!