How to quiet down motor

[marops]

Hi All,<br /><br />1980's J/E 35HP Tiller Outboard<br /><br />This engine is LOUD. Mechanically sound, but sitting next to this thing is annoying enough to warrant ear plugs.<br /><br />What things can I do to quiet down the motor or insulate the noise?<br /><br />The cover does not have any insulation, the carb is open, and the exhaust is above water [as should be].<br /><br />Any ideas on what I can line the engine cover with? Can I rig some sort of noise-suppressing, but non air restricting device on carburetor? Can I rig an extended exhaust system with rubber tubing that follows down shaft into water?<br /><br />Any suggestions much appreciated!<br /><br />Cheers

 

[DJ]

Re: How to quiet down motor

You can install a foam lining under the hood. The foil backed stuff works best. Just make sure it doesn't interfere with anything.<br /><br />There is no air silencer or cleaner available. The hood isulation will help.<br /><br />Do not extend the exhaust. It was designed with that backpressure in mind.

 

[G DANE]

Re: How to quiet down motor

All JohnnyRudes above 15HP was made with an intakesilencer since 1976. It you havnt got any, getting one will help some.

 

[dajohnson53]

Re: How to quiet down motor

I know a lot of people that spend long hours hanging on to a tiller handle outboard who wear ear plugs or ear muffs routinely. Other than the suggestion of replacing an intake cover that may (or may not) be missing from your engine, that's the only thing that will help, imho. Putting a proper type of sound deadener (laminate) inside the cowling will help a little, but the huge majority of the noise is probably coming from the exhaust.

 

[BF]

Re: How to quiet down motor

This is the main reason why I like to have a little kicker to use for trolling on my 16' aluminum, instead of using the 25 hp "main" engine -1970 'rude 25 hp-. My 80's 15 hp 'rude is less than 1/2 as loud as my 25 hp when trolling. My 6 hp johnson is a shade louder than the 15 hp. I also have a 2 hp johnson that is noticably louder than the 6 or 15 hp for trolling. It doesn't have reverse or neutral either so it stays in the boat house a lot. The 6 seems about right. The 15 runs smoother, but is a bit bigger/heavier than needed.<br /><br />Oh, and I find it reassuring to know that I have a backup to get home with if the primary engine has some problem.<br /><br />Brent

 

[marops]

Re: How to quiet down motor

Thanks for the responses!<br /><br />I just took a trip to local OB shop that specializes in older models and picked up an old intake silencer for just a few bucks that'll fit. They also were strongly against anything around the exhaust. Stopped by Lowe's and picked up some foam to glue inside engine cover. I don't expect silent running but it should help. Lucky I've got lots of quality earplugs!<br /><br />Cheers

 

[G DANE]

Re: How to quiet down motor

It shouldnt be THAT loud, if you find its sweet spot in rmp instead of hitting it all the time, it will produce a nice humming sound. That is if silencer is on and foam intact under hood. Mine was a 1984.

 

[jimmbo]

Re: How to quiet down motor

My dads 1980 35hp Evinrude had an air silencer in front of the carb, and the exhaust on it was buried deep in the water due to the thru-hub exhaust. The only exhaust above the water line was the idle relief.