Stripped thread

[Nicko]

My pal has managed to cross thread one of the bolts which fastens the rocker cover to the cylinder head on his R1100R (2000). Subsequent attempts at repair with tap and die have resulted in the destruction both male and female threads

Can anyone suggest a fix short of replacing the cyl head?

The bike is rideable with neglible oil loss.

Thanks guys

 

[cookie]

helicoil in the head & a new fixing stud?

pity you're in leeds, i have an M6 helicoil kit.

 

[Tarka]

Even better than a Helicoil is a Tymesert ( or Timesert ),as it`s a thinwalled solid insert rather than a spring type....

Assuming of course that there`s enough 'meat' left in the damaged area to install an insert,if it`s on a cast pillar like the lower right one on my 1100 head....

 

[cookie]

not had much joy with timeserts. in fact i've avoided then ever since the head came off my XR250 where a couple of timeserts came out.

don't you need a much bigger hole than a helicoil?

 

[Grizzly]

Helicoil's the best bet

A helicoil, done properly of course, is stronger than the original.
The hole size required for the M6 Helicoil tap supplied with the kit is 6.3mm. but if the original M6 thread is completly stripped, the hole will already be about 6.3mm and ready to tap. A kit is not very expensive but unless your really confident you know what your doing with them? (especially in a blind hole!!!) - get you local engine rebuild shop or similar, to do it for you - or practice on a blind hole in a spare bit of alluminium first before touching the cylinder head!!

Cheers.....................Grizzly

 

[Tarka]

don't you need a much bigger hole than a helicoil?

If you do,then I`m talking about a different type.

Roy Gardner fitted what I thought was a 'Timesert' to my barrel stud thread after a previous Helicoil had failed. Its diameter wasn`t much different from the Helicoil,though it was a bit longer,and it kind of looked like a black,non-spring Helicoil....

We have thread inserts in work which are quite large in diameter,effectively being a male threaded barrel with an internal female thread,but I`m not sure of their trade name. This type wouldn`t be suitable in the application above.

 

[Nicko]

Thanks guys.

Will forward your suggestions. Who supplies Helicoils?

 

[cookie]

Thanks guys.

Will forward your suggestions. Who supplies Helicoils?

i bought mine from the snap~on man and they're actually "Recoil" brand not helicoil.

i'd guess about £35 but that doesn't include the drill.

edit: just a thought. might not be a great idea to let someone who's bolloxed up the female AND male threads in the first place attempt the repair

 

[Le singe]

Had exactly the same problem with a damaged 8mm thread in my cylinder head.
Drilled and tapped it for a Recoil 'heli-coil' then found I hadn't any left!
The only repair inserts easily available here were Timeserts.
Other than a small radius being needed on the face, the insert needed exactly the same thread as the Recoil.
In my opinion,done correctly,the Timesert offers a better repair. I have seen Recoil heli-coils bite onto a fastener then either wind in or out.

 

[thornley]

Helicoil

This thread (pun intended) had me searching the garage. I've got an eight millimetre kit including the drill, tap and fitting tool with 8 inserts. Anyone gets stuck in the North West ASK. Might save a few quid and a load of messing. To stop the inserts grabbing use a bit of thread lock on fitting.