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Vintage YZ125 Help !A

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Going to go all the way, have motor out and all the other stuff in process of painting and restoring, new plastics, graphics, etc.


Couple of questions:


1.  Anyone know what flywheel puller fits a 1979 yz125?  I'm leaning towards 27mm but need a second opinion before i order on line, or borrow from local shop.


2.  transmission problem:


- Symptoms - issue only in 4th gear.  any other gear is fine. - I dont experience any grinding or rattle with transmission.  no debris in oil.  the tranny doesn't pop out of any gear.


the tranny does seem to lock up only in 4th gear.  i'll try and explain "lock up"       if you bypass from 1st, 2nd, 3rd, skip into 5th and 6th all is well.  If you shift into 4th at a good speed, the bike feels like it wants to stall out, then normal, then stall, etc while you are in 4th (not slipping, but causing the motor to stall out as if friction is happening in tranny.  If you are in 4th gear and going very slow, the bike will stall out and then the tranny seems to be stuck in 4th gear.  takes a lot of moving back and forth and pushing down and up on the shift lever with some good force!


has anyone ever experienced this?  when i open it up it will be interesting to see how a tranny would want to lock up in a certain gear, but all other gears are fine?


Again no slipping, no noises, just something to do with 4th gear is causing enough friction to lock up tranny.......post your input and I will post what I try and find later this week.




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Ya one of your shift forks is worn or bent had it happen to me on this one bike long ago a 1982 DR125 it wouldn't shift into 5th etc either case the tranny has to come apart.

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