I don't claim to know all the answers to the 11s' popping out of 2nd gear, however when I rebuilt my gearbox I compared the new 2nd gear with the old and found a .040" difference! This, coincidently, is ironically, 1mm. Kawasaki reps at Americade repeatedly denied any knowledge of this problem, but it seems like they mis-specified the dimension to their supplier or were shipped a bunch of mis-machined gears. I know from my own bike that it never jumped out of gear enough to wear .040" off the gear and that there were no iron filings in the crankcase when I disassembled it. I think that the big K screwed a lot of us over.

Have you checked to see whether the part was superceded? It's not uncommon for early model parts to be superceded by later model parts that are superior. :wink:

they had over 50 % failure rate on c models.my 91 c had a new 2nd gear 3 times by 24k miles...............................jackoffs.fucke m