Just finished setting up a new air cooled 53mm cylinder, everything looks perfect on paper... 190 deg. exhaust dur. ( matches our pipe), piston goes perfectly flush with the bottom of the exhaust port, and have .034" squish. Checked compression after a couple warm-ups, and it is at just over 195 psi, will probably be a good 200 after the rings seat! We usually run 180-185. This year i am going to run straight 110 race gas rather than blending it. Is this compression too high? I haven't calculated the compression ratio yet, but I am sure it's up there. Thanks, Dan.