TOPIC:

Right, the tensioner mounting bolts on my gpz750 barrel, one of them has obviously previously had the threads stripped and instead of helicoiling, the previous owner has taken it out to 8mm, what do people suggest? Do I go with the 8mm thread, probably helicoiling it anyway? Do I try and have some kind of plug made up and drilled and tapped back to 6mm? Or do I ditch the barrel, get another with good threads? I'm gonna be boring to 810 anyway. Can't see any cheap barrels for sale right now though....

I wonder if a 6mm timesert would fit snugly?
I'm sure any decent machine shop can weld up the hole and redrill to factory specs, but that may be a little pricey.
If you go with a bigger bolt, you may have to drill out the tensioner, too.

If not a tinesert you could tap it to the next size that work's red locktite a bolt and
bottom it tight then drill and tap to 6mm.

I'd have it welded shut, drill and tap for 6mm.
Steve

Welding would be the right way but I could fix it and not have to
leave it at a shop for a week or two.
I know not every one can or has the resource's to do this repair in their home garage
between the shop at work and my little shop it'd be a no big deal repair for me.

Thanks guys, I think I'll ask in work if they will do it - weld it and re drill and tap, (I work for a large British aero engine manufacturer in the defence sector - probably only one, so you guys can probably guess!), they should have all the capability for this I think.

When I worked at E&J as a welder, it was frowned on my bringing my own stuff in to weld. Company policy. I was there three years then quit to be a carpenter. They offered me my own department but I hated going to work and coming home in the dark. Never looked back. The company closed the next year. I heard they stiffed the older guys on their pensions.
Steve

Had a chat with some of the guys, and I think it might be worth going with something like this (attached), what do you think? I have material left to remove to tap out to the outside thread diameter (M10 ish)

I saw them back in the 80's. Too big for some things. Do you have enough meat to do it?
Steve

Yeah I reckon so, just about. You can buy similar ones on ebay, less than £6 delivered

I remember them from back in the 70's to fix cracked car cylinder head's that
were cracked into the plug thread's.
Drill and tap the hole screw it in then you would drill a small hole down through the thread's and
hammered a pin in to keep it from coming back out.