Very loud and short squeak noise at idle

[Badad]

My Mariner 20hp two stroke (at least 10 years old)runs like a clock. The only worry I have is one or sometimes two very loud and short yell from the engine immediately after a hard run when I put it in idle gear. People on the dock turn their heads and ask - what was that?<br />It has done this for quite some time but I would appreciate any advice on this in case I need ot adjust/replace something before I get a serious breakdown.

 

[bobrock]

Re: Very loud and short squeak noise at idle

sounds like a bearing to me ...

 

[btatum]

Re: Very loud and short squeak noise at idle

question?<br />does it seem to skip or shudder when this occurs?

 

[Badad]

Re: Very loud and short squeak noise at idle

Thank you both for bothering to reply.<br />First bobrock I don't think it's a bearing. Not a crank bearing anyway as it gives a really loud and short noise maybe a few seconds after dropping throttle. Usually I have made it to neutral but it has occurred also when idling in gear. On top of this it has been like this for a good 100 h and several years of running.<br />Then g8orb8 yes you may say it shudders as it runs on idle but it has never stopped during this noise. In fact I don't think it has ever stopped without manually switching it off.

 

[btatum]

Re: Very loud and short squeak noise at idle

i don't think it's a bearing noise either, i am thinking a possible vacume leak, can you run it with the cover off ? if so you may be able to narrow it down to an area of the engine and inspect it from there. i had a 45 that had a squeal at times at idle but ran fine, it turned out to be a gasket that split and under the right condition it would whistle.

 

[Badad]

Re: Very loud and short squeak noise at idle

Yes this sounds more like it.<br />Do you know location of possible gaskets?

 

[chuckz]

Re: Very loud and short squeak noise at idle

Check between the carburator and reed assembly and then between the reeds and the block. Spray a gas oil mixture around the gaskets while the engine is idling. If the speed changes, you've found an air leak.

 

[Badad]

Re: Very loud and short squeak noise at idle

Most greatful. I'll report back in a few weeks when I have been trying this out on my boat which is 200km from here.<br /><br />Midsummer party starting now in Sweden so there'll be many more loud squeaks and other noise soon.<br /><br />Skål!