Best sound insulation for a one-cylinder Yanmar?

[shemandr]

One banger's tend to not sound smooth. Everything seems to vibrate in harmonic motion. Ear plugs only dampen the noise in your ears. You still feel the thump thump thump in your shoes and all else connected to the hull. Turn up your ear pods or get a three cylinder Yammie.

 

[Jim 5757]

I'm with Ted! +1 on soundown - made a big difference on our M28. I agree that new mounts help too.

 

[druid]

I'm not sure if the surveyors and insurance companies are as Draconian in the US as they are here, but be sure you use insulation rated for Marine use (ABYC) if you don't want a nasty surprise the next time you try to renew your insurance. I think the stuff they use in automobiles is acceptable, but spray-foam may not be. I know the actual Marine-rated stuff is WAY expensive!

druid