Re: Motor too noisy..any ideas ???
There's an online company I bought some insulating material from a few years ago for my large and small outboards. They specialize in noise reducing materials and actually had something called an "outboard kit". The material is a typical looking foam sheet with contact glue on one side and sliver reflective material on the other. The foam has a thin layer of heavy vinyl to dampen sound. I bought this stuff because both of the engines I was working with were very old and the original material was falling off, etc.
I do believe it made both engines a little quieter. It was certainly more substantial than the very thin open cell foam that was in place on the old Johnson V6.
However, the principles of sound transmission just don't let you do much with cowling insulation. First, you need to leave the air passages open. Sound insulation depends very, very much on completely shutting off the sound source. A tight fitting door will have an exponentially better ability to lessen sound from the next room than a door that is even open just a crack. On your engine cowling, those little air passages - again tthey are ESSENTIAL - will let a surprisingly large amount of sound through from the engine. You can't do anything about that and shouldn't even try.
Secondly, almost ALL of the noise of an outboard comes out through the exhaust port on the leg, and through the prop hub. The prop hub is of course below the water, and that's a good muffler. But there's still a lot of sound that escapes, and there's absolutely nothing you can do about it.
You should try that kind of foam (foam w/ heavy vinyl layer), and you might hear a difference, but it won't change from noisy to quiet - most you can expect is "not so noisy". For me it was worth it, but most likely not noticable to anyone else.
Good luck.
