My 01 426 decided she didn't want to start on her own anymore. Might have sat too ling between rides, but oil was changed and air filter cleaned frequnetly. Either way, with a pull start or "poppin'" the clutch down hill, she fired right up and ran fine. I took it into the shop for carb cleaning and valve adjustment. They think the cam chain jumped time or the valves clearance was too tight, because I have bent intake valves. (leak test shows 60% leakage... and i was riding it like that?! I am no mechanic, butI do question that...) My delima is this: If they are gonna rebuilt the top end, what would YOU do to increase performance while you were in there? I can probably afford an extra $300 or so for upgrades vs. stock. They gave me a ballpark of $1000 to $1500 for the topend rebuild. Right now, they are looking at the bottom end. (Which should be fine!) The bike is stock, and I trail ride and hillclimb.