I recently bought the Bachman bros race bike from Iowa and am having problems with fouling plugs. I run 94 octane with Klotz Super at 40:1 , 420 main jet, 40 pilot, air screw out 1 3/4 needle at middle clip. I am an intermediate rider, so its not like i'm lugging the bike in the mid-range all the time. Upon starting cold it seems to be immediatly loaded up, rev it up repeadedly (get it on the main jet) and it seems to clean out, but if you hold it on the main it will start popping like the plug is on the verg of fouling. I have cleaned the power valve and it is not sticking that I can tell, but after riding hard, if I stop at an intersection and kill it, wait a few minutes, start it up and take off again it will almost always try and foul out. I always turn the gas off when we stop so I know it isnt the float or needle leaking by and I have new main seals both sides, so it isnt pulling crank oil in. Any help would be appreciated.