Back wheel locked up

[swissdean]

First for me. Freshly rebuilt motor. Shim gap is .005 ( I understand minimum is .003). Rode it down the street and as I moved into 3rd gear back wheel locked up and motor stopped. It wasn’t top end as it felt bottom end. Kickstart was jammed solid. Pused it back and open d casing today and all looks fine. Piston is seated nicely in kickstart arm, pin is in fine.. kickstart mechanism is turning fine. No bits in casing to suggest anything broke. Chain is right tension. Can’t figure out how to shrink post pics here, else would share. Any ideas?

[nastro azzurro]

Tooth broken off from a cog? I’ve had that…..

[swissdean]

Yep, tooth broke off 2nd cog was the reason.. is this likely just bad luck or anything that I did in the build that could have caused it to watch out for? I triple checked the shim gap but it was at the tighter end ie .005. About to rebuild tonight with an Indian gp200 gearbox I have. Any watchouts and tips ( beyond what I read in sticky’s book) welcome

[nsaints]

No advise other than Stickey's book

Curious - what gearbox is it that lost a tooth on the loose 2nd gear. Genuine Innocenti, or something else?

[swissdean]

Was a genuine Italian gp200 gear.. 2nd.. I read in the book 3rd was weak but !not 2’d.. I’m hoping it was just old metal fatigue

[al pushpak]

Was a genuine Italian gp200 gear.. 2nd.. I read in the book 3rd was weak but !not 2’d.. I’m hoping it was just old metal fatigue

Isn't it the early pacemaker box that's weak on the 3rd gear cog ?