My 70 GS 350 has a leaky bowl. Symptom; no gas in the morning or after sitting for a while. Could be the float seat or the bottom plugs. What's the fix?
I would suspect the well plugs are leaking. Call Cliff Ruggles or visit his site HERE he has a kit available to seal the wells for good.
If it's the stock carb, it could be the well plugs. Take off the base and check the secondary well plugs. If they're brass cups with staked marks or little aluminum discs with o-rings, those leak all the time. Do a leak test with compressed air and soap/water solution and check for air bubbles. If there's bubbles, you need to drill out the old plugs and install threaded plugs with marine-tex epoxy on them. I have a thread showing how I did mine here: http://www.v8buick.com/showthread.php?242604-Q-Jet-Quartet&p=1982826#post1982826
Bottom plug repair is well covered in our book. Don't forget to pressure test the front plugs, we see a LOT of leaking front plugs these days. The pressed in brass cup plugs disappeared by 1969, replaced with swaged in aluminum plugs. They are less prone to leaking, but should ALWAYS be checked during rebuilding. I'll say it again here as it appears in our book, "dabbing epoxy over leaky plugs is like cutting your arm off and putting a bandaide on it". Remove the plugs, tap the castings and install screw in plugs coated with Marine Tex, it is a permanent repair. I would add here that JB Weld is USELESS for this task. 99.9 percent of the carburetors sent here for work repaired with JB Weld show leaks right thru the glue. As far as fuel leaving the bowl, it either evaporates, leaks out the bottom plug(s), or drains back. Drain back can be eliminated by leaving the tiny clip off the needle, or going to a solid fuel inlet seat......Cliff
