Paulieboy72

Rebuilt 12a stock, modded nikki, new plugs, wires. Starts good, runs then floods out after 5 min. Have good, strong spark on three of the four wires, original coils. Could weak coils cause this? Carb clean and floats set to spec. Also the secondaries are getting fuel on top of them. Any help would be great

Carl

iTrader: (2)

It sounds like the bowl float valves are leaking. Next time you start the car, watch the fuel level through the observation windows. I suspect that you will see the level slowly rising. I have experienced that before. If that is the case, follow the directions that others have suggested of burnishing the needles and maybe the seat. It can be a pain. I ended up finding un-obtanium grose jets that after a fair amount of fiddling solved the problem.

To me, fuel on the secondaries while the car is idling indicates overflowing bowls. And I assume that the bowl vent is clear. You previously reported fuel coming out the top of the vent, so if that was occurring the vent line(s) should be clear.

Carl

Paulieboy72

I have taken apart the carb. The bowls were half full. I am cleaning it all again and burnishing the needles. The old needles were a little worn, the spring was so I am using new ones and burnishing them. I did find something odd taking the carb apart again, I noticed that there is what looks like a weight it's brass and large, however according to the carb manual it has no place. The only weights and check ball are for the ACCELERATEr pump on the diagram two in total so don't think that was supposed to be in one of the jets

Carl

iTrader: (2)

When you pull the carb apart, the bowls are always going to half full (assuming it was just running) because the floats take up quite a bit of room. What was the level in the sight glass before you took off the top?

How was the weight in one of the jets?

Carl

Paulieboy72

I have no idea, it looks like a weight but it is very large about 1/4 long brass and about 3/16th in diameter. The carb diagram doesn't show any except the two for the ap. The bowls when I took the top hat off were half full that's all I know

Paulieboy72

Coils checked out good .9 ohms and 8000 ohms on both. Bought new ones but they also checked the same so I'm sending them back

Paulieboy72

I'm told there is supposed to be a one way check valve on the fuel return in the engine bay near the carb...what does it look like and where do I get one. I don't think I have one

KansasCityREPU

iTrader: (9)

The oneway restriction on the return fuel line is a silver cylinder about midway in the rubber return line right off the carb. It has an arrow etched into it for flow. You can see it here on my engine.

Paulieboy72

yeah, i dont have one of those, can i get just a standard check valve for fuel?

Paulieboy72

btw that is a beautiful engine bay

Paulieboy72

Would a cracked float cause flooding while running?

Seniorchief

I haven't dealt with a carbs since the 1970's, but yes it can cause flooding. A carburetor float needs to be "buoyant" in order to do what it's designed to do, and that won't happen if it's cracked. But I look forward to reading the responses from the forum carburetor experts to see if I'm wrong.

Paulieboy72

Ok the Crack is at the top near the tang, but I noticed as it's cracked right there it doesn't allow the needle to open