I have just recently developed a gearcase oil leak on my Ty250a. Just below the countershaft sprocket and above the shiftshaft there is a hole that is cast in the crankcase that appears to be for a shift fork shaft from inside the case. The oil is seeping from that hole. On my Ty250c this hole is closed. Is there a seal on the inside or plug on the outside?

Thanks! Steve

Gday, I think the one you mean is a plug for the shift shaft and the rubber plug is the seal for the hole. Best bet would be to lay the bike over and clean the area really well, and put a smear of 3-Bond over it. That should do the trick.

Cheers,

Stork

It is not the large flat black rubber plug that is leaking but rather the hole directly below the sprocket. Even in the pics on ebay this cast bushing is open.

I've gotta go and have a look at mine the suspense is killing me

Ok here is what a LH case from a TY250D looks like.

Edited June 2, 201016 yr by feetupfun

Mine leaks somewhere in that area also. Usually end up with some of it on the chain so I just consider it a plus ;0) (doesn't really leak enough to cause any problems).

Alan

And here is my TY250A motor showing the hole/plug that searay is talking about

Thanks Feetupfun! You are spot on! In your pic of the "d" model the hole is closed and in the "a" model pic it looks to have a plug.

To avoid any confusion the shaft hole in question is just to the left or 11:00 position from a straight line between the shift lever shaft and sprocket shaft. My "C" model is a closed casting also but there is no plug in the case on the "A" model. In looking at the Yamaha parts breakdown it appears that there is a plug shown in the diagram. Maybe that is what I need, if so I can have a machinest fab one.

Thanks! Steve

The plug I believe it may be is # 19 in the shifter #1 breakdown of the online yamaha parts diagram. Only thing is they show the same plug on a c model also so I may be wrong. The plug is only a $3 part and quite common for many other models #90334-10006-00

I got it fixed! A $3.17 Yamaha part. the little plug is tapped in and sealed. Hopefully there is not an internal problem that caused it to be pushed out.

Thanks!