stripped plug hole

[Octain]

Any suggestions on the best/easiest mothod of repairing a badly stripped plug hole? I had to use a 2 foot breaker bar to remove the plug.

If the head has to be removed it'll turn into a 'while Im there' job for sure.

[doctorgonzo]

Any chance just a thread chase might work? If not next step would be an insert , you could probably do that without pulling the head.

[Octain]

Any chance just a thread chase might work? If not next step would be an insert , you could probably do that without pulling the head.

The threads are in really bad shape. A thread chase would result in getting metal fragments into the chamber wouldnt it??

Im afraid Im gonna have to drill, tap and heli coil. Of course I'll try the easiest route first but in any case I think whatever I do its gonna require removing the head.

[Nessism]

First of all, do NOT helicoil. Get a solid insert, like a Timesert or similar. Helicoil brand sells these so maybe I'll back pedal on my first statement, just don't get a common helicoil since they tend to come back out when you remove the plug. Auto parts stores typically sell kits like you need - get 14mm thread.

Edit: if you can find a Timesert kit, that would be best. Maybe they rent them in your area? Failing that, check this Helicoil solid insert kit http://cgi.ebay.com/ebaymotors/HELIC...item4a9c3afad7

[doctorgonzo]

The threads are in really bad shape. A thread chase would result in getting metal fragments into the chamber wouldnt it??

Im afraid Im gonna have to drill, tap and heli coil. Of course I'll try the easiest route first but in any case I think whatever I do its gonna require removing the head.

I've used a chase without removing the head (on my old head), I liberally coated it with grease so the bits stuck to the grease rather than falling down in the head.

[Nessism]

Grease on the tap will do it. Plus, a few aluminum bits that may fall into the chamber are not cause of great concern. If you rotate the piston until it's at TDC you can suck out the chips with a shop vac anyway.

[Octain]

I may try the thread chase with grease, good idea. If that wont work I'll try to find a timesert kit. Im sure a parts store rents it.
Thanks fellas!
Perhaps I wont have to pull the head. Not for this project anyway, hehe.

[Octain]

Grease on the tap will do it. Plus, a few aluminum bits that may fall into the chamber are not cause of great concern. If you rotate the piston until it's at TDC you can suck out the chips with a shop vac anyway.

Another good idea!

[piester]

if its on your 850 im probably going to be parting my old 850 if you want the top end

[Octain]

if its on your 850 im probably going to be parting my old 850 if you want the top end

Nope. The 1k.

Thanks though!!

[oldgrumpy]

recoil inserts..... for stripped holes...

i,ve repaired a stripped plug hole,,, which was no.2 using a company in melbourne called recoil..... and i,ve had no dramas at all ... in the kit you get the tap and the locking coil..... this company provided ferrari F1 for kits at the F1 race in albert park ,,when ferrari had blown some plugs on their heads,, it gave the company product alot of good reports....that was with M.S. driving ,he won that weekend ...their coil locks in as permant ,,and the thread is actually shaped a triangular shape similar to the thread ....which surprised me when i first saw them ...as i did work there in the toolroom.. and doing tooling maintenance as a contractor....hope tis helps... heaps of grease on the tapand piston tdc... worked for me ...regards david from kaniva