http://www.lengner.net/motogears.htm look at the pictures at this link. I cant find a problem with these gears. But the bike would pop in and out of 4tn gear in. feels kind of like chain slap, or when really riding hard (racing) thought I was missing a shift but realized after testing that it was a gear box problem. 4th only... I saw a number of other posts with similar symptoms but it appeared their problems were all easily identified once they split the cases. I cant really find any problems with mine. One of the pictures shows slightly rounded gear cogs (not teeth but cogs or claws, whatever they are called) but nothing that would seem to cause major problems. Anyone have experiences in this? Do I replace everything or what?