1964 Yamaha YG1

Hello all,

Just purchased a 1964 Yamaha YG1 80cc. Seem like a great little bike. Look forward to riding her. Just had a few questions that I was hoping someone could answer.

What type of oil should I run in the gear box? I was reading that some people use 10W40 and even some use ATF in the 2 stroke gearboxes? I was leaning more towards the 10W40.

What fuel to oil ratio should I use for premix? I think I read 20:1 on an old brochure I saw online...kind of hard to make out the text though.

Also along with the gearbox oil, anybody know what the capacity is and how to tell how much is in there? There doesn't seem to be a dipstick or anything...at least that I can find. It does leak oil out of the gearbox so I want to make sure that I don't run it too low.

Any help would be greatly appreciated. I've spent a couple hours browsing the internet and had little luck so far.

Thanks

Nate Warner