Muffler Modded my Craftsman - One Tuning Question

[Stein]

I muff modded my 36cc Craftsman last night. I stayed conservative and added one 5/16" hole, stuck a rod in it and flared the rear out and the front in to get a bit of direction out of it.

Cut the limiters and tuned it. Got the L to pass the "rotate the saw" test after idling for a minute or two so no gas pooling. Good trigger response from idle. Set the idle and it runs and idles better than before I started.

The question is the H side. The way it is set now, it is right on the border and just fades in and out between four stroking and not when in the cut. Do I want to tune it leaner to just get rid of the four stroking in the cut?

BTW, it really woke up this little saw. I could go to 3/8" as the stock muffler has two 1/8" x3/8" slits in the rear which would put me about 80%.

With a freshly filed safety chain, it was cutting 9" oak rounds in about 8 seconds. I tried it on a 16" mulberry which just buried the bar and it cut without bogging. Can't really lean on it but I was impressed with the improvement. Might have to get a real chain and open the muffler up to 3/8".

 

[Evan]

if it burble at wide open throttle while out of the wood then under a load you will most likely never hear it burble(fourstroke)

 

[rmh3481]

>>The question is the H side. The way it is set now, it is right on the border and just fades in and out between four stroking and not when in the cut. Do I want to tune it leaner to just get rid of the four stroking in the cut?<<

You want the engine to four stroke until its under load. Once you start cutting the four stroking will end. When you are working the engine heat is the result. Oil from the fuel mix is lubrication and the gas is cooling the piston/cylinder so it wont melt. A little excess is much better than not enough.

Your on the right path with your muffler mod. There is a link at the top of the forum to a sticky about muffler mods. Check them out, they might give you a few new ideas on how large to make the holes and where they should be.

Best wishes,
Bob