Hello all.
Never had an owner's manual for my bike and I couldn't find anything in my Clymer's; does anyone know the gear ratios for the transmission? Just curious as to how it compares to a TW200 that I recently acquired.
Thanks for any information.

Does this help?

Vintage Yamaha Enduro Fans - 1968-71 DT1 factory service manual (yamaha-enduros.com)

A copy of the 1971 DT1E and DT1-MX Owner's Manual is also in the Tech Library.  The front part has the specs for the Enduro, the DT1-MX specs and info starts on page 39.

Thanks for that, never had seen this before, awesome bit of knowledge.

Lolipop 50, if you look right at the top of this page you will see a header that says tech page.
Should you need any further assistance from manuals,klick on that and they are probably there.
They're free to access. There's also a Clymer manual for sale on E Bay.com right now that covers all the 250s from that era. It's a rather salty $140.00 though. I know why you want it too. All the tuning stuff for the DT1 is in there including porting maps if it's anything like the CT1 manual.
Dave.

Yes I saw it from a previous response, everything you need is there.
I never noticed that until 2 days ago, there is even a riders manual, which as the original owner I can't remember ever having one, funny what 50 plus years does to your memory  . 
Thanks for your reply!