Stripped Bolt Hole Options

[FJRBluesman]

There are three options, in order of preference:
a. Tap deeper with the existing size and use a longer screw: easiest. Measure the depth of the bore with a piece of wire, and compare to the stock fastener length. If you've got 3+ mm of usable bore past the stock screw length, go to the longer screw.

Be careful going deeper. You may not have enough meat to grip or you could crack the case if you force it too deep. The hole could be conical shaped and your measurement would be slightly deeper then you can tap.
All I'm saying is be very careful as you go forward to make sure it is all done logically.

Good luck.

 

[user 213]

If you're going to attempt to tap the existing hole deeper, go buy a bottom tap in the size needed. Taps commonly come in three styles - Taper, plug and bottom. Taper taps have a nice point that makes starting in a non-threaded hole easier, plug taps have less of a taper, bottom taps almost none, (which is fine for existing threads when working by hand). Also worth noting is that taper and plug taps push the chips forward, bottom taps pull the chips back out of the hole. They are designed to tap blind holes to maximum depth. Exactly this application.

Helicoils are easy to install. Gaskets are cheap. It's worth it to do this right the first time and be done with it. It's highly unlikely you'll ever need to deal with the problem again if you helicoil it now.

Or just stuff some JB Weld in the hole, coat the bolt lightly with grease for a release agent and snug it down. (disclaimer - I wouldn't do this and am not responsible for any negative results.)

 

[SCRider]

Good advice from all and thanks to all.
In the spirit of taking it one step at a time, I ran a 6mm tap into the hole today. The original bolt now threads in but, of course, there was not much to cut into and I dared not tighten the bolt very much. As soon as I complete the rest of my repairs/maintenance I will take a shakedown ride with the fairing still off. If I am lucky, the leak will not be there. If I am not, then the next step will be either a Heli Coil or a 7mm or 8mm tap and new bolt. . . and a new cover gasket from Gary at Mondak.

I agree that the right way to fix it is to remove the cover and use a heli coil but you might want to try running a 1/4-20 tap into the hole. Being .014" larger, you would probably get enough meat to get a decently tight 1/4-20 in there. Looking at Howie's pictures, going up to an M8 screw would be pushing it.

 

[MCML]

That is pretty cool of you, Howie! If I have to go to the next step a 7 or 8 mm bolt of the same length sure seems like a viable option.

OCFJR, I had the JB weld out this morning to fix an unrelated problem. I fiugred that it was easier to attach a "T" nut than drill out a broken off EZ Off.

 

[JimLor]

Interesting thread for me. I stripped the bolt at 4 o'clock about 2 years ago. I just stuck the bolt back in and covered it in tape. Never leaked. I occasionally think about using the stuff we got at EOM last year. One of these days I'll get around to fixing.

EDIT - oops, I stripped a bolt on the stator cover. Never mind.