'79 yz250 trans issues...first post

[79yz250]

Hey whats up guys...this is my first post here. I just picked up my first bike ... 1979 yz250 for $50 from a friend of mine. It needs work but im sure i can get it going. I know it needs a top end bad and i have the motor out and the head and cylinder off of it...i have the trans cover off as well. I have a few questions...sorry to be a noob but i'm trying to learn. (I'm a Ford tech so maybe i can return the favor when ur ford breaks lol)

1. Someone at some point welded yes welded the nut on the crankshaft on the trans side. is there a reason for this? are they known for loosening up?

2. I dont think the trans is shifting right and i am going to take it all apart as soon as recieve my manual. Are new parts available for the trans or are they usually just swapped out for a known good unit?

3. anything in particular that goes wrong with these motors/bikes that i should know about? its air cooled with no power valve.

thanks alot and sorry for the leangth.

 

[VenomRS4]

I recently picked up a 1979 YZ250 Too! I cant wait to get out on it.

Im not completely sure about the trans but my guess would be that you would have to swap the parts from a known good unit. The Bike bandit site says that the parts are discontinued. You might find some NOS parts on e b a y or something but thats pretty rare.

As far as common problems, i have not heard much bad stuff about them. But my bike didnt have a spark when I bought it so maybe keep an eye on electrical.