*Toning Down That Genny*
By: Jaden
22 December 2005

As with most older generators, they’re LOUD!! There’s simple a spark arrestor on the exhaust with does absolutely nothing for noise control. Other Rubies have modified their exhaust systems with success. Figured it was my turn. Before my wife’s old car went to the junkyard I salvaged the new muffler for this project. Just finally got a chance to do it.

I bought a couple pieces of ¾" threaded pipe and a couple of 90 degree fittings. The pipe screwed into the engine block perfectly. Then it leads down to the muffler. I welded a piece of angle iron to the handle and dropped it down to support the muffler. The muffler bolts to the support slightly loose to allow for any vibration.

The next problem was adapting the ¾" pipe to the 2" (IIRC) pipe for the muffler. Stood there and thought about it. Finally decided to cut the end off the spark arrestor to see if it’d fit over the muffler pipe. Out came the saw-z-all and a few moments later I had the perfect adapter. It fit awesome! So with the MIG welder on low the spark arrestor was welded to the muffler. This wasn’t very easy. That spark arrestor is pretty thin stuff.

Notice that the weld is on the face of the muffler and not out on the pipe. This is because the metal is thicker where the pipe goes through the muffler wall therefore it makes a stronger joint. The spark arrestor then screwed into the fitting as you see below. Walla…done.

There is a trick. Obviously you can’t take an oval muffler and spin it to thread it onto a piece of pipe when the muffler is snug against the cart’s frame. Looking again at this pic.

Thread the pipe into the engine hand tight. Then put the 90 fitting on. Use a pipe wrench on the fitting and tighten till both the fitting is tight and the pipe in the block is tight. Make sure the fitting is pointed in the direction needed. Next, thread in another pipe hand tight and install and 90. Tighten these the same as you did before. Once the bottom 90 is tight and where it needs to be, back it off perpendicular to the cart. Then screw the muffler on. Now using the pipe wrench, lock onto the bottom 90 and use the wrench to tighten it. The muffler will swing toward the cart. Once it’s where it needs to be, bolt it to the support.

I fired it up and the noise from the muffler was just a purr. There was some ambient engine noise, but still it was much quieter than it was before. I observed some small leaks in the joint between the arrestor and muffler so I gooped the JB-Weld around it for a seal. Once it hardened I started the motor and there were no leaks. Seemed a little quieter.

I cut the protruding end of the muffler pipe off to eliminate a shin banger.

I think I’ll get some fiberglass pipe insulation to wrap the exhaust pipe with so incase I bump into it I won’t get burned. It might help with the noise too.

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