Welding plugs in quadrajet

[Hulkjoegan]

I'll soon be rebuilding my quadrajet to address some hard starting issues, both hot and cold. I figure while I have it off, I could turn down some aluminum at work and have our very experienced welder weld them in there for me. It's free and more permanent than epoxying them in. I don't know if they're leaking or if they're my issue, but might as well, right?

Any feedback or opinions?

[VileZambonie]

Epoxy works fine

[Henry]

Hi Hulk:
As a long time owner of 3 q-jet carbs over the years, I would have to say that the bonded (or glued-in) welch plugs is the #1 weakness of this otherwise well engineered carburetor. As you are aware, the different rates of leakage will cause different symptoms: hard cold starts or hard hot starts or just stalling when otherwise running ok. As these carbs get older, repairs on the welch plugs are not as good as the original factory bonding...I suspect some glues are better than others considering the fuel exposure, heat exposure and thermal expansion/contraction of the aluminum.

I myself have been wondering if I could solder or braze in welch plugs on my next rebuild as a permanent fix.

I think your idea of welding in plugs as a permanent fix is a good idea BUT I would caution you to do a test weld in case the welding destroys the carb: I THINK the Q-jets are die cast aluminum with a high content of silicon(to facilitate the casting process) and this does not accept weld. Can you get a scrap carb and test the weld process?

Regards,
Henry

[blazer74]

Let's not weld on the carb.

You can use Marine Tex to seal the well plugs which works very well but also you can remove the plugs, tap the holes and install Allen head plugs with the Marine Tex on the threads for a permanent repair.