Hello,

I was stupid enough to break the bolt that holds the rocker gear onto the cylinder head and it has snapped off with just about half a millimeter showing.

I have tried using a hammer and a cold chissel to tap the stub around but it won't move. It had been tightened to 30lb per poot so I think it is quite tight. Does anybody know how I might be able to remove the stub of the bolt.

Thanks

Richard.

The options are:

Tap it out with a sharp centre punch (sounds like that ship has already sailed)

Drill it and take it out with a screw extractor (unlikely if it's jammed, sounds like it had bottomed out in the thread to do that)

Drill it out really accurately to leave only the thread left, you can then pull that out (this is almost impossible unless done on a really sturdy pillar drill or mill)

Drill it out and helicoil it (Probably the most likely option) - had to do this on a few motorbike cylinder heads for the exhausts (M8), never had a problem doing that, even in situ on something as tight as a GSXR750.

you dont say which engine, but if it's a 1.6 or diesel you should be able to unbolt the cam bearer cap from the head and take that off to a machine shop to be drilled out etc