Chainsaw Repair

If you are going to experiment it might not be a bad idea to first tinker with a lesser expensive saw first .

Now if all you do is rework the muffler and some port polish ,maybe widen just a tad ,you will see results .You haven't really changed the porting scheme any just allowed it to "breathe " better .

The port time area opened really doesn't need much correction unless you can raise the compression which will allow a higher exhaust opening .Now if you do that the time area opened for the tranfers will need some correction ,the intake etc . As the speed increases the time allowed for each portion of the cycle decreases and thus the port sizes will need to be altered to compensate for this . It's complicated but simple in principal .