Scooterotica

I have threaded my bottom exhaust bracket stud in the casing on my jet, I have already tapped it out to a 10mm previously. Would it be better to get it helicoiled or is there a good chemi-metal that will hold it....or do I bite the bullet and get it welded and re-tapped? The top stud is fine.

Aren't they supposed to be threaded?

Helicoil should be fine, if the thread is damaged.

Helicoil or weld/retap in my opinion

I wouldn't trust epoxy metal in a stressed area

Stripped the thread on mine, so tried chem metalling a stud in as a quick-fit bodge. Didn't work - the heat made the chem metal go soft and crumbly. Insert or welding is the only answer I'm afraid...

If its been tapped to 10mm and is now stripped I think it will be to big to take a M8 helicoil.
you will need to get an insert which has a thicker wall than a traditional helicoil. Welding and tapped is the best option but its an engine out to do it ....mind an insert is to if you want it perfect.

Good luck

Nooooo

Either get it welded (if enine stripped)

Or better (still) 'Time Sert' it. From memory M8 is a 10.8mm drill size.

If the 10mm thread is good,I would be tempted to get a piece of 10mm studding,file the end piece until a 8mm die can be ran down the necessary length and cut off enough 10mm thread to fit in to the casing i.e. a stepped stud.

I already had tapped for a 10mm and drilled the chaincase to fit so putting in a 10mm stud back isn't a problem, what size would I have to drill to take the 10mm helicoil and is there enough meat in the casing to take it out to this size? Saw those time serts , quite pricey though and again don't know if I can go as far as 10.8mm.

I think his 10mm thread is goosed as well chris.My m8 helicoil set has a 8.3mm tapping drill(just measured it for you so your knackered there.)
you could use a 10mm helicoil and use the stepped stud method as just mentioned.
Ive just done a similar job for a friend,his was worse as he,d tried to drill out a broken stud and veered off at a strange angle,i had to reposition the hole on a milling machine,plug it with an oversize ally stud and redrill and tap it,was a pain.

beedspeed sell various stepped repair studs, some may be odd thread one end e.g. a whitworth /13mm other end, but they work. is it the casing tailpipe one? ive done one out to 11mm and made the casing hole bigger to suit,not original but works.