2001 XR100 cylinder head

My son crossthreaded the sparkplug into the cylinder head. Is there a
sparkplug repair kit available or will I have to re-tap and insert a
helo coil? Can I do this without removing the cylinder head?

You will need to helicoil the head. Either remove the head, or
try this trick:

Position the piston well before TDC.

Fill the chamber with grease. Drill, tap, and place helicoil.

Crank the engine up to TDC. The grease will push out the
shavings.

You will then have to flush out the rest of the grease with
some type of solvent. This will be messy.

I have never tried this, but have heard of it from others.

Personally, I think it would be just as much work to remove
the head.

-Jeff Deeney- DoD#0498 NCTR UTMA BRC COHVCO AMA
'99 ATK 260LQ-Stink Wheels '94 XR650L-HellSickle
We don't stop riding because we get old, we get old because we stop riding.