1982 YZ250J Flywheel Puller???

[VMXSteve]

Does anyone know the size of the flywheel puller for a YZ250J.   It is NOT the common 27mm.
It is smaller than a 19mm (smallest I have) and I suspect its a 18mm.   Can't confirm on Ebay etc, and want to make sure I order the correct size / type.

Need to also know the tread direction and pitch.

[shelpi]

I dont know, But I have made plenty of pullers, try your alxle and or pivot bolt, just take note of the pitch probobaly around 1.25 and should be right hand thread, have you got an old bolt store/tin even if ya got the wrong diameter with a given/ known size bolt you could at least use it as a thread pitch gauge, measure the ID and go to a fastner shop

[alexbrown64]

Steve, i have the 83 YZ125 and he old Yamaha requires a puller which is just a hollowed out bolt which has a 18mm x 1.5mm thread and is about 30mm long.  I bought a fancy one from UK and it worked great.  Normal thread direction.
Cheers,
Alex

[Tim754]

Steve if your intending to purchase some parts or labour from your local Yamaha specialist for the YZ, try borrowing one off of them   

If successful, copy it...

[tony27]

If you measure the inside diameter of the thread you should be able to work backwards to find the size, M18x1.0 will measure just under 17mm, M18x1.5 will measure just under 16.5mm.
It's a rule of thumb that was used lots when I was still working as a toolmaker & works as a general rule

[rocketfrog]

Genuine Yamaha puller available at your local for around $17. As Alex said, it is simply a counter bored bolt. As it is tightened into the rotor the hollowed counter bored section of the puller comes to a stop and bears against the end of the crank spindle which jacks the rotor away from the tapered shaft.