stripped exhaust head bolt stud?

[unclejemima]

I took my exhaust off to get powdercoated and I put it on again last night, but the one of the two bolts that holds the exhaust headpipe to the engine would keep spinning. Its pretty tight, but it will not snug up.
Can I use lock tight or such on these bolts?
Can I re-tap the threads? Would it be in the aluminum on the block or is there a steel stud inserted typically for the head pipe bolts?
FYI 1984 YTM225DX
Thanks kindly!

[Grizzlypeg]

Helicoil insert would be the best fix. You can get kits at car parts stores.

[200XMichigan]

That lock-tight tread repair sucks. Someone used it on a cam bearing cap bolt in an engine I rebuilt and the bolt came out fine, didn't notice the threads were no good till I went to torque the cam back down. All the treads came out like a little epoxy mess. Head to get a new head gasket which was only available in a kit, which I had just bought. But amazingly I emailed Versah and they sent out a head gasket from Tokyo, Japan for free. But anyway threat repair epoxy sucks. Heli-coils are great. Haven't used time-serts. I guess they are better but more expensive.

[daniel_250r]

if you are really red kneck like me and too lazy to leave the shop tap the hole then find a bolt that fits the threading, next cut the bolt off so it is flush with the head. next drill the bolt in the center and tap the center of the bolt to the threads that the stud is. i did this and have had no problems for 2 years now

[anderson8687]

helicoil is the best way, but you may be able to JB weld it, fill the hole with JB and then screw in a bolt that is longer than the stud was (cut off the head of the bolt before screwing it into the JB Weld filled hole) then put your head pipe on and use a nut on the bolt you put in. dont be aggressive with tightening it, a little at a time so it doesnt spin in the JB W. also make sure to give it plenty of time to cure up good.

[tri again]

I took my exhaust off to get powdercoated and I put it on again last night, but the one of the two bolts that holds the exhaust headpipe to the engine would keep spinning. Its pretty tight, but it will not snug up.
Can I use lock tight or such on these bolts?
Can I re-tap the threads? Would it be in the aluminum on the block or is there a steel stud inserted typically for the head pipe bolts?
FYI 1984 YTM225DX
Thanks kindly!

oh man, I'm having exhaust stud flashbacks...and actually how I got my first job working on airplanes back in the 70's. but I'n sure I've forgotten more than I ever knew.

I like the ideas suggested so far and inserts are the best but they do eat a lot of space, diameterwise. and not sure how much aluminum meat you have to work with.

I've had helicoils come uncoiled and really psssssss me off but I'm sure that was operator error or not enough / or the wrong kind of beer.

someone said that the 6mm studs strip out to a perfect (something) diameter so you dont have to drill, just tap to whatever size that new hole is.

now, do we want fine threads because there are more per inch?
or coarser threads because its aluminum.

Exhaust studs are something I oil/spray all the time on all the bikes just in case I ever have to redo them.
and the smoke kinda freaks people out but marvels mystery oil smells pretty nice.

Hey, btw, whats the deal on 2 strokes that look like they have coil springs holding the exhaust headers on?