Borked cam cap bolt hole

First off I'm glad I found this place.

I was tightening my cams down on my 1980 KZ 1000 and stripped the bolt hole for one of the bolts on one of the cam caps. Another forum suggested I just repair the thread with a heli-coil. Like the hair lip that I am, I just dove right in a gave it a try. And of course I used the wrong drill bit to drill it out. Since then I have become very good at helicoil and time-sert.

So now I am hosed. I have a J head that I have thought about putting on the bike, but I really was hoping to save that project for a while until I can do a whole strip down on the bike.

Can the hole be repaired? Any suggestions?

I am sure there is a solution.
What size drill bit did you use?
And did you do anything else to the newly oversize hole?

All I did was drill it out one size over, but that is enough that the helicoil doesn't fit.

I was thinking of finding a machine shop to fill and tap the hole for me. But so close to the cam bearing, i'd be afraid of damaging the cam.

hmmm could I helicoil the hole with the correct size for the bit, then slink the next size down into THAT helicoil? A double helicoil? LOL talk about ghetto....

You mean the hole you drilled is too big foe the Helicoil tap?

Jay

Install a larger helicoil.
One that is meant for the size hole you drilled.
Don't forget to consider SAE or USS threads also.

Then you can drill the hole in your cam cap slightly larger...........OR...........
Put in a stud that is a different size on each end;
one end screws into the head, the other passes through the cam cap.

There is stuff called Form-a-thread that may work. It is like a JB weld kind of stuff.

Don't use helicoil - has a tendency not to last in that specific application. Take a look at Big-Sert, they have thicker walls and are far superior to helicoils. With the thicker wall dimensions, you may find that the wrong drill size actually was the correct one for Big-Sert. Do a search with your browser - comes right up. They come in standard and metric.

A good friend of mine had the majority of his bolt holes stripped out, and used Big-Serts with great success.