broken header mount bolts

[Pacman]

I have three (yes three) broken header bolts on my '79 GS850. One for each of three cylinders.

Anyone drilled these and used an easy-out on them before? Would it be easier to just replace the cylinders this fall?

The bike runs good right now (after all the work I've put into in the past two weeks). I get an occasional pop out of the exhaust that could be the result of air getting in at the header but it's not too bad. I'll probably wait until cooler weather here before doing either but was looking for input on which would be easier.

The good thing about changing cylinders would be that I could also do rings, etc at the same time.

Thanks,
Chris

[chef1366]

How much bolt is sticking out?

[OklahomaPomade]

Good first question...if you have enough to grab with vice-grips, you should be able to work them out.

When this happened to me, I drilled them out with a smaller bit then followed with an 8mm bit, followed by an 8mm tap.

Worked great.

[Pacman]

Unfortunately, they are broken flush. An issue I didn't notice before I bought it 2 weeks ago. (I would have bought it anyway but would have offered less).

I've drilled and used an easyout on a countless number of bolts over the years. Some are easy as the bolts are soft and not rusted in. Some are darn difficult.

OklahomaPomade, did you drill them out to a larger size or is 8mm the stock size?

Thanks for the replies,
Chris

[OklahomaPomade]

MINE was 8mm. Metric taps can be a little hard to find. Try Pep Boys if you have one.

I only had one break. The others came out ok. I used one of the good ones to determine the correct size tap needed.

Having the tap was nice also because I was able to clean up the threads in the other holes as well...lots of "steel on aluminum" corrosion in there.