Why does the kz 900 have a bad second gear

I have always heard that the 1976 kz 900 was natorious for blowing 2nd gear. I have a 1974 Z1 900 and 2nd gear is great, but my buddy just bought a 76 kz 900 and it is popping out of 2nd gear, like the other day we were out cruising and we were in 2nd and all of a sudden hus popped into neutral and he revved it out to like 8 grand. My question is why is the trans in the 72-75 Z1 seem stronger than the kz 900?

It's not, your friend's bike most likely has worn dogs and/or shift forks.

a lot of people have the gears under cut, this will keep the tranny in the gear you want

2nd gear is a common problem in 900/1000s especially in high horsepower bikes with sticky tires.

Yes. It is the smaller of the two gears that goes first.

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