GS1150 cylinder head bolts sheared ?

[Roger Chatterton]

Does anyone know if it is possible to repair the thread in the crankcase that the "Cylinder head securing bolts" thread into ?
Situation looks like the RH head has been removed at some point before I owned the bike (1150 GS Adv 2003 vintage, 30K on the clock), maybe to replace the head gasket, and must have over tightened one of the bolts.
Whilst in for its first service today and tappets being checked, mechanic noticed that one bolt was loose, went to tighten, and found it wouldn't tighten up. We therefore suspect that the thread in the crankcase has gone !!

He's going to strip back & remove barrel, and see what can be done, but is it possible to "sleeve/re-thread" to effect a reliable repair ?

Apparently I was lucky that the bolt had not come fully loose, and got mixed-up with the rocker assembly-that would have been fun.

Not a happy bunny here, not least as I have to expect a fairly hefty repair bill, if it can be done- and I'm certain that the problem's not the fault of the previous owner-wonder how long it would have lasted ?

Any chance that the original BMW dealer might help here ?

 

[Flipfly]

If there is enough meat in the material to drill it out more, then you could get it helicoiled.

These are actually stronger than the original thread.

Good luck, I'd guess a Helicoil will be possible.

 

[Flipfly]

Any chance that the original BMW dealer might help here ?

Yeah, they'll supply you a brand new engine!!!!!

 

[Roger Chatterton]

Yeah, they'll supply you a brand new engine!!!!!

Wot, not even a brand new bike.....cheapskates !

 

[Roger Chatterton]

If there is enough meat in the material to drill it out more, then you could get it helicoiled.

These are actually stronger than the original thread.

Good luck, I'd guess a Helicoil will be possible.

Yeah, I had the head on my old R50 heli-coiled for the exhaust pipe retainer, but I guess I would have to have the engine removed for heli-coiling into the crankcase ?, or could it be done in-situ....also, is special equipment needed for this, meaning, I don't think my service garage has this sort of facility

 

[Steptoe]

, is special equipment needed for this, meaning, I don't think my service garage has this sort of facility

Electric drill.

Helicoil thread cutter. ( Comes in the helicoil kit)

Helicoil insert. (Comes in the helicoil kit)

 

[Roger Chatterton]

Thanks for all the info -I'll pass it on , and see what happens.... I've had a look at a couple of Googled "helicoil" results, and maybe things are not such a problem as I first thought.
As Steptoe says, apparently you get the helicoil kit, and the correct drill size, and take it from there -all this is providing there is enough "meat" around the hole in the crankcase to be able to drill- ??

 

[Vern]

Mine done this a couple of months ago.I managed to get a helicoil in by the skin of it's teeth,but there wasn't much metal left when the stud pulled out.That fix lasted about 20 minutes.I ended up,machining a 14mm bolt down,and drilling and tapping the inside of the bolt out to 10mm,then drilling the crankcase and tapping that out to 14mm then loctiting the new 14mm boss in place,then put the whole lot back together again.

Have fun

 

[Roger Chatterton]

Managed to have a look at my bike, in bits ....
the lower, rear right bolt on the RH cylinder has got a load of engine casing in the thread, so does look as if it has been over-tightened at some time, by some previous owner or BM service person ( was serviced by Cannon for the first 18K miles).
So, it looks as if there is plenty of metal around the bolt hole, only slight snag is that there is an oil gallery running into this space as well, just to complicate matters. I am hoping that it can be drilled and sleeved OK -looks likely . Apparently there is a better alternative to Helicoil, which mechanic showed me -the Helicoil looked like a very tight spring, whereas his preferance is for one that looks a lot more like a tube, threaded inside & out, but works in similar manner -can't remember the trade name though. Anyone know of this- Rick, the mechanic has used this several times before with success (not on my bike though !!!)

All I have to worry about now is the bill......but, if he hadn't found this, it would have been a serious bill, with probable engine & rocker damage. That's the up-side anyhow !!!!

 

[cookie]

it's called a time-sert. i've only ever had one fitted & it failed, so i'm not a fan.

it was replaced with a helicoil which was fine. i'm sure others have had the reverse of that experience.