Stripped screw holes

[Roy]

On both of my Mikuni 38 carbs, there are stripped float bowl screw holes in the body of the carburetor. Any suggestions? I was thinking about buying slightly longer screws, and putting a nut on the back side. Any better suggestions? 1971 Yamaha xs1-b.
Thanks!

 

[cra-z1]

I would be looking at the Time Certs for professional looking job. Maybe Helicoil also. Nuts on the backside may work for Larry the backyard mechanic, thats Leroys (AKA the hack) brother. They make some SS self tapping inserts but have never tried them. I would be concerned about cracking that corner with the self tapping. Might have to get creative with Time Cert as it may be hard to set them. Probably have to red locktite them in place
https://www.timesert.com/html/mtrcsert.html

Is that a 4mm or 5mm screw?

 

[Mailman]

I did the same repair on my XS2, it’s outlined here, Edit: If you have access to a drill press, it would make the job super easy and perfect.

https://www.xs650.com/threads/mailman’s-xs2-a-full-on-restoration.51520/page-25#post-546624

 

[Its been a long time]

I would be looking at the Time Certs for professional looking job. Maybe Helicoil also. Nuts on the backside may work for Larry the backyard mechanic, thats Leroys (AKA the hack) brother. They make some SS self tapping inserts but have never tried them. I would be concerned about cracking that corner with the self tapping. Might have to get creative with Time Cert as it may be hard to set them. Probably have to red locktite them in place
https://www.timesert.com/html/mtrcsert.html

Is that a 4mm or 5mm screw?

Timesert is a great repair. Highly recommended. But does the Timesert insert sit flush with the float bowl gasket face?

 

[gggGary]

An old cheaters trick was replace stripped screws with an SAE screw that was just a bit bigger
Tread carefully, hate to see you end up with 1/4 20 float bowl screws.

If you do push it up to the next size (M5's).... for all practical purposes, an SAE 10-32 and M5 are interchangeable.
Just an FYI...

 

[Roy]

The carb bowl screws are M4 X 0.7

I would be looking at the Time Certs for professional looking job. Maybe Helicoil also. Nuts on the backside may work for Larry the backyard mechanic, thats Leroys (AKA the hack) brother. They make some SS self tapping inserts but have never tried them. I would be concerned about cracking that corner with the self tapping. Might have to get creative with Time Cert as it may be hard to set them. Probably have to red locktite them in place
https://www.timesert.com/html/mtrcsert.html

Is that a 4mm or 5mm screw?

 

[cra-z1]

Yes the Time Cert would need to sit flush. The counter sink used withTime Certs may not be the best idea. If I used the Time Cert I would grind off the shoulder and insert with red loctite flush with the carb surface. Mailman's approach seems solid.