Hi All, A friend came by today with the plans of replacing the piston in his '04 XR650 with a Wiseco 11:1. I had downloaded a manual off of here for an '01, I think, believing it would be close enough. Anyway, we pull down the engine. Everything looks pristine. Tons of cross-hatch on the cylinder walls. Slight wear on the skirts of the stock piston. No doubt it was still within specifications. The new piston installs easily. everything is going great. Now, the book says to turn the engine over until the "T" mark on the magneto aligns with the mark inside the cover, and the two timing marks on the cam gear should align with the head surface. No problem, everything lined up. We triple checked it. Put the bike together and kicked it over and TAPTAPTAPTAPTAPTAPTAPTAP! Something sure as hell isn't right. I pull out my borescope and have a peek inside. It looks almost as if the intake valve is beginning to open just as the piston arrives at TDC, and the two get awfully damn close. I couldn't see contact, but it looked probable. We tore the head cover back off. depending on how you look at it, the timing marks don't line up quite exactly. Certainly not a tooth off, I thought. But well, it could sorta be interpreted as maybe the cam could possibly be advanced a tooth to correct it. So we did. And it sure looked like it was a mile off. But that bike fired right up and ran fantastic. Big increase in low end torque, and it seemed to rev freely throughout the rev range. Easily shot up to 95 mph with more to go (this particular bike is street legal). Does anyone have an explanation for what we witnessed? The timing by any account is off, but you can't tell by the way it runs. Do Wiseco 11:1 pistons hit stuff? Was the book wrong? Was there a difference between the model in the book and this one? Why can't I get laid daily? Thanks!