Chainsaw Repair

Hi,

I might have rushed things a bit (I try to get all my workshop stuff done when the fiancee is at yoga...)  I think I might have opened up the exhaust a little too much.  I havent been able to try the spaghetti method to check the percentage.  Also, I've heard that you shouldnt open it up more than 80% of your original exhaust port.  Does this mean 80% of the exhaust port size in the cylinder... or the exhaust port at the outside of the cylinder..

I've attached a couple pics to show what I did.  Any thoughts?

I dont mind buying a new muffler if i have to.  I'll take more time to do it next time...

sorry, my quote button isnt working for some reason : 

"My chainsaw mufflers are slightly larger than the cylinder outlet of the exhaust.

The outlets of the mufflers are larger than stock. The cookie cutter race saws have outlets as big in area as the exhaust outlet of the cylinder."

Do you mean the cylinder outlet that the exhaust gasket attaches to? (the one i refer to as outside cylinder in my diagram).  Reason i am asking is there is quite a bit of difference in the opening inside the cylinder versus outside at the exhaust flange side...

026 MM

Greg, every saw is different , my 066 Mag Stihl with it's dual outlet muffler comes with a full baffle inside the muffler over the exhaust port . It puts out all the power I need for what the saw is running at stock.
When I played with tuned exhaust pipes on my race saws years ago when most members here weren't born yet, I experimented with the "exhaust outlet " stinger on the pipe by cutting off lengths of the stinger until the the timed cuts in the log cant dropped in Elapsed Time, that point in length was where I got the best h.p. Same example goes for outlet diameter, the stop watch never lies.

Cool, so I guess I don't have to worry about my modified opening being too big then.

I might still buy another replacement muffler and do a better job of the mod