What material should I use to re-insulate my outboard motor cover to reduce it's noise?

Question

It's a 1993 Evinrude 200HP 2stroke of course. Obviously, it's going to be loud regardless, I would just prefer to quiet it down a little. I'm thinking dynamat?

Answer 1

If your using the Hoodliner, it might be a little thick.  I'm concerned about cooling air clearances, heat build-up and FIRE.  I know Evinrude had a liner but I don't know who the manufacturer is, but it was only about 1/2 inch thick.  The safest way to go is to see if one of the dealers in your area has an old hood, that's in good condition, laying around, from a blown power-head.  Then make a trade.  You could check on line used parts suppliers.  I'd also ask at the auto shops, there might be something thin you can order.  Good luck!

Answer 2

you would be wasting your money and time in lining inside cover of hood. Noise you are hearing is coming from exhaust of two stroke by the prop.

also, lining inside would restrict air flow to engine and cooling of the heads.

its best to buying your next boat with four stroke engine.  

Answer 3

use some soundmat - see the link

Answer 4

Stick with the manufacturer on this one. The wrong design will destroy your engine. The smallest pieces of free floating insulation thru the reed blocks and needle bearings is not good.

Answer 5

You can find sound absorbing foam in the Mcmaster-Carr catalog. http://www.mcmaster.com/  Type in 'sound' in the search box and all the sound-related products will come up.

For an outboard cover or and engine box you'll want some sort of lead-lined sound absorbing foam.  The Dynamat website has a short FAQ about which products to choose. http://www.dynamat.com/