Hi Guys, I'm doing a dry run on my transmission – DT1-F, everything seems to be working OK but there's about .30~.35 axial play in the shift drum. I checked parts drawing for shims or spacers- none-and there is no reference in the shop manual, Is this normal? JC

If you are saying drum moves in and out almost 3/8 of an inch I would say "not normal"

I'm not super familiar with that model but looks like there should be a "guide"...  #7 in the link below...  that would locate the drum?

www.partzilla.com/catalog/yamaha/motorcycle/1972/dt2/shifter-a

Sorry, I didn't specify, .30 mm so around .013".

The frame # is F, the model # Is E and the motor is stamped just DT-1 and all the numbers match,
so I'm not sure what to quote.
JC

There's no spacers or shim on those so not easy to reduce it although i don't know what mine is for end play. Cases bolted tight when measuring?. No7 MarkT kindly notes is only for lifting the claw arm thing over the next pin--or something like that, so not there to set end play as such, or shouldn't be relied on for that purpose. Bottom line--i don't know. If you wanted to reduce it your options are limited. Could possibly add a thin shim on the right end. Left end might be difficult as there's a pin to locate the cam so shim would need to get past that. Other side of cam & the plunger might attack it--well that might happen if fitted either side of the cam. Just forget it & call it 'racing clearance'. If you 'do' alter it you have to consider which way left-right is best because you're either reducing or increasing gear engagement one way or other but only a gnats whisker. Shut eyes & carry on i think. Just a random thought--a previous owner hasn't made a center gasket for between the cases, as don't run a gasket.

Thanks,No gasket.I'm piecing this together with an early big tooth close ratio gearset and wanted to make sure I'm not missing something. Everything seems to work.Very diplomatic mentioning PO, you can blame them for everything. JC

I very much like the big tooth gear ratios as seemed fairly close & evenly spaced all the way compared to the overdrive 5th gear on the fine tooth later boxes. BUT--i broke 3rd gear big wheel twice. Once on my DT1 probably late ion the first year. This was racing hard out in MX but 'is' a fairly spindly looking gear. Came out the bottom of the case & didn't impress me lol. Second one i broke in later years in a 360 tweaked motor also in MX racing. Are you using the later selector drum with 3 independent selectors or the with one that wraps around the drum. Thinking back the later drum won't work with the early cases as no hole for the 4th-5th selector shaft. Sorry, just talking to myself.

Yes, that is a normal clearance. There were shft drum shims available for '74-75 YZs, but are hard to come by.

Well, i never knew 'that'. Always something to learn. Thanks. No6.
www.partzilla.com/catalog/yamaha/motorcy...974/yz250a/shifter-1