Shindaiwa Muffler bolts broken how to repair?

[mcambrose]

I have a EB630 and one of the muffler bolts broke off and I have tried to get it out with vise grips turning the bolt. It has turned some, but won't loosen. I think the bolt is somehow cross threaded. Any way this can be repaired?
could I cut it at crancase and then drillit out? Would there be enough metal left in the head to put a helicoil? Are there other suggestions? I have ordered another blower, but this one still runs fine if I can get the muffler attached again somehow. THe unit is about 4 years old, so i thought it wouldn't be worth putting a new head on it.

[ed2hess]

It is worth the try with helicoil... not necessary a good idea but I have run the units with a piece of bailing wire run around the unit to hold the muffler when I had only one screw.

[hole in one lco]

cut it at the head and drill it out and re tap

[CCWKen]

Weld a nut to the part sticking up. Then take it out with a wrench. If you don't get it drilled dead-center, you create even more problems.

[dfor]

Try spraying PB Blaster or Kroil on the bolt. Let it sit for an hour or longer, and try again with the vice grips. The stuff works well at loosening frozen bolts.

[mcambrose]

I was able to get the old bolt out with vice grips, but the threads were bad. I took it to a local machine shop and he put 1/4" fine threads in the hole. It works great now. Only charged me $2, but I gave him a tip. I also put lock washers on the bolts this time, so maybe they won't get loose.