Honda 250r Air Cooled Cylinder Questions

[feo_nuts]

Hello all! I have a chance to buy a super sweet 1985 250r air cooled for pretty cheap! Here is the predicament! The guy im thinkin about gettin it from said he was upgrading the head on it to a bigger one. He put it all back together and went to tighten the head bolts and the whole stud spins. The questions I have is... is this an easy fix? I've drilled out and retapped bolt holes before. I've also installed helicoils. Is this as easy as just drilling out the holes and retapping or helicoiling? Does special machining need done? Is the cylinder trash!? Well I hope to get some accurate feedback on this please. So if your full of trailprotrailprotrailprotrailpro......buy a yamaha! Lol!

[MTS]

well for one, air cooled r' is 81-84 after that they are liquid cooled. fixing a striped stud is just like any other, helicoil it..

[pablo]

If more than a half inch of the stud is left above the top of the cylinder I would double nut it. This means tighten two nuts on the threads and wrench the lower nut for easy removal of old stud.

Then install the new stud the same way.

[cr480r]

i ran an LT250 with very high compression for 2 years with 3 helicoiled studs out of six... all on one side too... no issues and i rode that bike alot.. some may argue that helicoils are actually stronger when used in aluminum.. I dont know, but they worked just fine.

[feo_nuts]

So there is no special "belling" or anything that I have to do to the holes? What about just retapping? Or would it be safest to helicoil?

[250rJAMIE]

Just get them heli-coiled,I have had the all the studs on the cylinder on my 83R heli-coiled and they have held up fine,Just dont go over tightening them or they will strip out again

[feo_nuts]

Awesome! What are the torque specs for the head bolts (nuts) please anyone?