I have a Kohler 1750 generator powered by a K91 4HP that I bought last year as a camping generator.
It had the typical Kohler "pancake" muffler on it when I got it.
It isn't "that" loud (to me anyway) I know that what is "loud" is subjective. I figure on putting this out under the back pull out of my popup camper while out at the campsite.I have a "2 way" fridge on board that runs off of either 12V (thru the on board power converter) or propane. I also have a 5000 BTU A/C that would be my main need for 110V. while out camping.
I found a much larger muffler for it via Ebay shortly after I bought the generator a brand new but probably 30 year old Nelson Spark arrestor muffler that is probably ~3" diameter and 10" long, meant to slip over and be clamp to a piece of 3/4" water pipe. If my K91 were threaded for pipe like some are, it would be 1/2", judging by exhaust port size.
I had somebody make me a flange out of 1/2" plate and I plan on using a piece of scrap 1/2" electrical conduit about 4" long that I bent via conduit bender to about a 45* arc
My plan is to weld the conduit to the flange (that will then bolt to the motor) then weld a short piece of 3/4 water pipe to the conduit as a sleeve on the other end of this piece of conduit to size up to the muffler inlet.
now the water pipe will hardly be seen as it will all be within the muffler except maybe for ~1/4" or so;
What I have in mind is much like some of the old minibike mufflers that had a standoff pipe between the muffler and engine; the old Snapper riders had something like this too. I have some 1/8X1/2 metal strapping that I plan on making a support with, for the other end of the muffler as a "standoff" from the engine
My questions are; will the conduit hold up to the heat OK? and also, being the pancake muffler bolted up flush to the block and its inlet was the same size as the exhaust port, my idea will have the exhaust dumping into a smaller opening (just by the thickness of the tube, which is about 1/2 the thickness of water pipe) most thinking on exhaust seems to be "bigger tube is better" for breathing... the amount that the conduit is smaller than the port, shouldn't choke off the exhaust "too" bad, will it?
Edited by dodge trucker, June 08, 2014 - 04:02 PM.