Hello I am working on a dirt bike for a friend and need to know what I'm working on. It is a Yamaha probably from the 70's or 80's. It it a mid sized kids bike. It says Yamaha on the tank, 50 on the oil tank, and Enduro on the exhaust shield. The only numbers I can find ar on the steering post. Stamped into it is 3A8-010152. There is also a sticker that says Vehical ID number 3A8 and also the month and year 08/79 The rest of the sticker had worn off from the the clutch cable rubbing.

I also need to know what oil to put in the transmission. By the fill plug it says 500 cc for amount. Also what injector oil should I be using. The bike was in a flood and everything has water in it.
Thanks
Kel

 

Can't help you with the year/model, but you can use Yamalube transmision oil and Maxima Super M 2 stroke oil for the injector

 

Thanks Red400. I have one more question. This bike was completely under water for 2 days so the 2 stroke engine and trans were full of water. I drained the trans, and blew out the cylinder with air, but what is the best way to get the water out of the crankcase itself.? I was thinking of removing the gas tank and oil tank (have to do that anyway to drain and clean) and tip the bike upside down with the sparkplug out and piston at BDC to expose the intake and exhaust ports and leave it like that for a day. Then blow out the cylinder again. Sound right?
Thanks

 

Actually the best way is to pull the head and jug and tip it upside down and blow it out with air.

 

Try this website


Yamaha Vintage Dirt Bike I.D. Guide: Off-Road.com