Mercury F6M problem

[Peter2673]

Hi

Mercury F6M 2 years old, less than 100 hours, serviced end of last season, first outing of new season it ran fine for half an hour, but then after 10 minutes at full throttle started to make a loud squealing noise.

The noise continued on reducing speed to idle, but after a few minutes stopped and the engine ran normally at half throttle. i then re tried full throttle and the noise again started after a few mins, and resolved after throttling back.

I'm not sure if it's a silly problem like a rubbing cowling, or something more sinister like a bearing failure.

I know a trip to the dealer is probably necessary, but they are 30 miles away, so a quick fix would be welcome if anyone knows what this is.

Ideas? Please?

Pete

[Fenlander]

Well first I'd have the cowl off and have a really good look as to what could possibly catch including as far as you are able the flywheel area. Does this OB have a timing belt... if so something wrong or catching in this area is a possibility and would be a crucial aspect to check.

On a more complex engine a seizing bearing due to an oil feed issue would be a worry but probably unlikely in your case.

Does it still pump water well?

[Peter2673]

Thanks Fenlander

Yes it pumps water well, and runs absolutely normally at full power apart from the noise.

It doesn't have a timing belt.

I'll perhaps whip off the rope start and see if any part of that is rubbing the flywheel.

P