alberio Loc: Casa Grande AZ

Both of my generators are fully enclosed, so I couldn't get to the crankshaft nut without taking the panels off. Fortunately my larger one has electric start.

jerryc41 Loc: Catskill Mts of NY

I made a little shed for mine to keep the noise down. Since it's on wheels, it's easy enough to move it back and forth to start it and add gas.

One mistake I made was building the shed too small. A larger shed would have reduced the noise more. Although it's double-walled with foam insulation between the walls, the noise still escapes. I found that I couldn't use the door because it got too hot inside, even with a large fan pulling out the hot air. Connecting the exhaust to the exhaust port on the shed isn't practical. Still, it does cut down on the noise somewhat, and it protects it from the weather.

TriX Loc: Raleigh, NC

You could substitute a larger, automobile style muffler, but it will take some fabricating. Considering doing that to my 6KW natural gas powered generator.

jerryc41 Loc: Catskill Mts of NY

That's well beyond my need. I saw someone online try that, and it didn't go well. I have a hole in the shed next to the exhaust port, so the exhaust gets out.

TriX Loc: Raleigh, NC

I’m thinking of an appropriate sized muffler off maybe a large golf cart or similar size engine (~10 HP) and then just a pipe with a 90deg bend and a threaded fitting to match the exhaust port and a couple of exhaust/muffler clamps to hold it to the frame, perhaps horizontally. You could actually use iron pipe+ a pipe thread fitting and an elbow, but the wall thickness will reduce the diameter. A go cart shop might have just the thing or a muffler and down pipe off a small motorcycle - maybe 125cc.

Just Googled “quiet muffler for generator” and got dozens of hits - going to check these out…

jerryc41 Loc: Catskill Mts of NY

That sounds like a future project.