Been driving me nuts! My "new" (98YZ)bike has been acting like it's lean,,hot pipe,detonating,pinging etc. but at the same time will foul plugs at least two a ride. Finally checked the compression again,first check(few weeks ago) was after the ALL new top end with no break in,it was 210. This time,after 5 rides it's now 240. psi. with stock squish of 1.3mm or about .055" I gotta tear it down to see if someone had cut the head or the cylinder base:banghead: Does anyone else been able to run this high of comp on 92 oct swill? Jetting is basicaly stock.with a new FMF gnarly pipe. (Second one in three rides) Geeeez i hate rocks!!!