New Soundproofing Foam-Insulation

[Saline Marina]

So I have a Four Winns 170 Horizon, 2000 model year. The green foam (sound deadener, etc) underneath the engine cover is starting to flake (etc) into little green flakes and dust I find all over. I'm OK with having to replace it, just have no idea what material(s) I should be looking for or some websites, suggestions, etc.

The dust is OK but I really don't like the idea this stuff is probably being sucked into the flame arrestor....

 

[rallyart]

The best material to stop sound from travelling through the engine cover is a heavy mat or sound dampening rubber that you can find in many auto sound shops. It's 1/8-1/4" thick. Basically in is just adding mass and vibration dampener to the glass on the cover. Next best, and can be put over top the dampening mat is a compacted rock wool mat that stops sound from travelling through it some but really does a good job stopping sound from reflecting. It's about 1/2-3/4" thick. Both of those would stop sound better than a foam. The rock wool also keeps the heat out, which is the best part about the original foam.
Getting the old foam off is a bit tricky.