[tommygraham]

Ill keep it short and sharp,
I was just re assembling my bike engine and as I was tightening one of the bolts which holds the inlet cam shaft in position, it snapped. The thread is not above the head level just to make matters worse. I am thinking of getting a set of left hand drill bits and drilling the core out, then using an ezy-out to try and get the little bugger out of there. I have thought of using my little butane pencil torch to heat up around the head, but I don't think this will make any difference. And yes, I was using a torque wrench set to the correct torque setting.
Thanks in advance, Tom
View attachment 1502

 

[fortytwo]

Have you got a dremel? Maybe you could use a really fine ball attachment to cut a slot in the top of the bolt which would then let you wind it out with a flat head?

 

[tommygraham]

Thanks for the suggestion, but I managed to get the bolt out about 2 hours ago. I bought and ezy-out set only for the left hand drill bits it had and managed to get the little broken bolt out. Ended up using a little right angle drill attachment because I couldn't get my drill in there. The engine is all back together now and I just started it. I will just have to wait until tomorrow when I can give it a good run.

 

[Aduro]

I'm hoping you didn't get any swarth or fragments in your engine or stuck in your oil? That would have been a very delicate job. Goodbye bearings of there is anything floating round in there.

 

[tommygraham]

I was very cautious of exactly that. I had someone hold a rag around the area I was drilling and only used a small drill bit running very slow. I didn't even create much swarf as the bolt span right out not long after drilling. The little amount that was created was contained to the dowel hole and didn't even leave the hole or touch the rag. I removed the small amount of swarf soon after with a few light sprays of RP7 and wiped off the floating swarf with a rag. I will be doing an oil and filter change before I start riding the bike regularly as an OCD measure. Haha

 

[clevermetal]

Pro-tip for next time:
Coat the drill bit and surrounding areas in grease. It catches the small bits of dust and makes it much easier to clean up.

 

[Slipry]

Pro-tip for next time:
Coat the drill bit and surrounding areas in grease. It catches the small bits of dust and makes it much easier to clean up.

This is a good tip esp for re tapping threds etc