Racing Fuel Systems

I have done this repair with 12-24 helicoils in the past. Now I have one that has had the helicoil damaged and threads destroyed that hold the helicoil in. And it has a 1/4-20 helicoil installed in another bowl position and it has pulled out.

Never did like those Demon bowl screws with the "allen" heads. Too easy to over torque and pull the threads.

Thinking Keensert or Time-sert solid inserts would be a possible repair, but have not found them made in 12-24 thread. Anyone made this repair?

The BG-installed heli-coils in a Demon I used to own pulled out due to poor installation. Couldn't get same size replacement inserts to hold, so I switched to the next size up in metric hardware, including heli-coils.

Took a minimal amount of extra clearance for the metric screws to pass through the fuel bowl and metering block holes. I actually like the Allen-head screws and used metric screws in the same style.

Good solution by Brad if it works for you. I’ve found when tightening Demon bowl screws with Allen key to only have the Allen key 90* bend resting on the side of your index finger and tighten with thumb on the other side. Agree they are easy to over tighten if using the long end of the Allen key in as normal. Good luck with the repair.

Further searching did not turn up any 12-24 solid wall thread inserts.

At this point, new plan is to tap drill/tap out 3 damaged to a larger size common bolt like 1/4-28, and screw/locktite in soft bolts, spot face flush. Then locate centers and drill/tap back to 12-24 thread.

Anyone have better solution?

You could drill the holes to 5mm and tap M6 threads. These are common and only a bit larger. 4.5mm vs 5mm drill size.
Is zinc weldable? Brazing might work. Weld the holes full and start over.