Chainsaw Repair

compression goes back to the same problem, how much port timing did you put in the motor , less port timing the more compression you can run unless you run race gas of some kind , same thing with your flywheel timing the more advance you run the flywheel the less compression you can run cause its going to get real hot fast . I donot like running any saw on pump gas above 175 psi on my gauge cause first in most cases it will blow up second it will not be as fast or last as long as a saw running 160 to 170 psi that has had the other stuff do to it , Most high test pump gas is 91 or so octane now and at least 10% ethanol so you have to consider what your have for fuel cause its no good building a saw that has to run on C12 or something like that if the saw is to be a worksaw not a weekend cookie cutter , another thing  the higher the compression in most cases the shorter the main bearing last , I got 7900's that are out there with tree companys that are 7 years old and work pretty much every day , I did see 2 this summer come back for main bearings from 7 years of work so that is pretty good in my mind