Coleman Powermate Generator

[Kevin K]

A few days ago my neighbor gave me a 4Kw Coleman Powermate generator, model 54400, he wanted to get rid of. The generator had been severely overloaded to the point it started smoking and would no longer produce power. I took it apart and found one of the circuit breakers had melted, a terminal had fallen off and shorted a couple of turns on one of the output windings. It was a simple repair: replace the circuit breaker, re insulate the windings, and it is back in operation. It has had very little use and is in great condition. Now to the problem: this thing is LOUD! You need hearing protection to stand anywhere near it. The engine is a Briggs single cylinder 8HP model 190412 and uses what can only be described as a tin can for a muffler. I found a quiet muffler that fits this engine on one of the web stores, but they want $100 for it! Since I already have a couple of quiet generators, there is no way I am going to spend $100 on a muffler for a generator that's not worth much more than that. Does anyone have any ideas on how to silence this thing at a reasonable price?

[GADavis]

Adding a quiet muffler won't really quiten this generator down much. It is a 3600 rpm unit and all them make a heap of engine noise more so than the exhaust does most of the time. Isolating it in a soundproff compartment is the best way to do it. It is considered a disposable unit that sells cheap and not designed for long term use.

[Andrew Mackey]

3600 RPM is LOUD. You can try a muffler designed for a large Kohler engine, they generally are more quiet than their B&S counterparts.
Andrew

[grub54891]

Had the same noise problem, Even hooked an old car muffler to it, Still louder than a rock concert! Sold the darn thing and now all is quiet!

[F. Moore]

When you modify the exhaust system you must be careful of exhaust back pressure affecting the performance, the more pipe you add the more restriction. I'd try adding a larger diameter pipe over the muffler if it's a round type and then turning it straight up with about 10ft of pipe if it's in a stationary position. I used to add two 10ft sections when I ran them inside while working on RV's with Onan's and they were really quiet.

[B.Sparks]

"Does anyone have any ideas on how to silence this thing at a reasonable price?"

Unfortunatly, no. It's not just the exhaust that's causing all that racket. Even if the engine had a perfect muffler, you'd still go deaf without hearing protection. There is combustion knock (30 times per second), a fairly big fan whirring at 3600 rpm, and the clatter of the valve gear. This all taking place inside a thin aluminum die casting that acts very much like a bell, covered with fins that act like tuning forks.

A considerable amount of acoustic engineering goes into the design of the better quality engines such as Honda.

You could enclose the set in some kind of foam insulated box but cooling would become an issue. I've hear of military personnel partially burying gensets while in the field.

[armandh]

loud is an understatement but outside with the exaust pointed away from the house it is better than no power and way worse than something quiet.