Here is some information for the good of the order. I just had my head examined, I mean modified by RB Designs in Portland, Oregon. I had him lower the squish band to .040-.045 running on high-octane pump gas. I believe stock is about .070. The modification seems to make the bike run very crisp, with an added bit of punch right off the bottom. As if this bike needed that. The bike seems to run cleaner without all the pinging and detonation I was experiencing before. I think I will need a flywheel weight now, as I ride off-road. But, I must say that one benifit that almost out-weighs any performance gains, is the lack of spooge running down my silencer at the end of the day. Really, the stuff drives me nuts. The rear fender splatter is all but gone too. The pipe showed a 1 1/2" dribble from the outlet, just enough to let me know the motor is safely rich. Anyway, it was worth it and I would recommend it to anyone who (like me) has not been able to clean up the carburation on their YZ250 through the brass. The proprieter requires a cashier's check, or money order, which is a bit of a pain but what the heck, it's still a free country. I have no affiliation with RB, and I am not receiving any compensation for this post. I just want to pass on my remedy. Take care and stay safe.