Shifter shaft end-play

[Scott Sappington]

74 250 silver engine, shifter shaft has @ .125 / 1/16" of end play. Whats is acceptable with out doing more damage / wear?  Whats causing this,a worn part, thrust spacer, or..?
Are the upper center frame to engine braces (bolt on) crucial, or are they over-kill. Must they be in place for a racing application. Thanks, Scott

[Kip Kern]

No real given end play on shafts in the KTM engines, I always start with a .020 shim on the right case end and go from there (shift shaft).  You want some end play so things dont stick. Some engines had shims there and some didn't. I just built them by feel after the cases were assembled, if too much slop, I opened them and installed more shims to my liking.

[Kip Kern]

Crankshaft was shimmed to spec in manual, just wanted to bring this up.  No measurements for the tranny area.