RE: Stripped glow plug threads on engine head.
Send it to Clarence Lee. He will install a Heli Coil. I think it is something like $8 + shipping.
Clarence F. Lee MFG Co.
10112 Woodward Ave.
Sunland, CA 91040
818-352-3766
this is not cost effective to do your self. The threads are 1/4"-32 which is a special size. You would have to special order a whole Helicoil set to get one coil. It would be cheaper to buy a new engine.
Enjoy,
Jim