FAQ Input: Repair gas tank mounting hole at front of frame

[MattR]

Question:
The M6 bolt which secures the gas tank at the front of the frame got stripped out. The frame looks like it has a threaded insert. How do I repair this?

Answer:
The wall thickness of the threaded insert will allow you to retap a slightly larger metric bolt. I used a M7 bolt (which is not very common by the way). I retapped the hole with M7 threads being careful to get the threads cut straight. The new M7 hex bolt uses a 11mm wrench for tightening. However, Allen head bolts are available too.
----------------------------------------------------------------------------------------
Add other input if you know how to replace the threaded insert with a new one.

[gasgasman]

I've had good luck with these.
Unlike the Helicoil, they have a shoulder to lock the insert in place.

www.timesert.com

[MattR]

Those look like a nice idea.
Do they come in a M7 thread OD with M6 thread ID? Or is it a M8 thread OD?

[gasgasman]

The inserts come with their own specific taps.
Here's the engineering specs on the inserts.

http://www.timesert.com/html/engineeringdataM.html

[gasgasman]

MattR.
I got to thinking.
The timesert won't work on the front fuel tank mount, since there's no solid frame to tap into.

There's another fastener called a "blind rivit nut", which Ford uses to mount roof racks on vehicles.
Here's an example.







http://www.gesipausa.com/rivent.htm

I can snag a couple from our body shop if you like.

[MattR]

Thanks for the followup idea. Right now, my M7 thread retap is still holding. If I encounter an issue in the future, I will definitely keep the blind rivet nut in mind. It looks like a good application for it.

Another application this would be good for is to fix my seat bracket. The rivet nut on the rear bracket likes to strip sometimes and I have to crimp/ovalize it a bit for the bolt to stay tight.

[gasgasman]

.........so I should snag a few from the body shop?

[MattR]

Originally Posted by gasgasman

.........so I should snag a few from the body shop?

Sure, a couple would be good to have on hand. Thanks!
By the way, can a standard rivet tool/pliers crimp them in place? Not sure on the installation procedure.

[Hawkeye]

My bike had the same problem. I used a rivnut from a late model KX subframe available at any Kawasaki dealer. To install, I simply drilled out the frame to make a tight fit to the rivnut, tap it in place and then pull the blind rivet portion tight to the frame by installing a M6 bolt and tightening it until the rivet bottoms out. My fix has lasted 4 seasons, no problems.

[MattR]

Originally Posted by Hawkeye

...then pull the blind rivet portion tight to the frame by installing a M6 bolt and tightening it until the rivet bottoms out.

Thanks! I thought this method may work but wasn't sure if it would buckle/crush the center portion correctly. Sounds like it worked out fine.