I saw a rebuilt 064 on Craigslist for $700. The fella put a Cross Perfomance 066 Top end conversion kit in it, which jumped it from the 52mm piston to a 54mm, which some of you know, some may not. I would be inclined to believe the jump in cc’s will be negligible on starting without a de-comp valve as well as the jump in power? Is this a common upgrade on 064? I know there are all sorts of mods/upgrades to be made from chainsaw to Diesel engines for more power but some turn the engine into a grenade in waiting. I suppose it depends on the rebuilder in some cases.