carb flooding

It sounds like a too rich situation. But is it only after then engine has been shut off? After that puff of black smoke, is it then OK, or does black smoke continue? If only black smoke once, here are two ideas.

The first is your electric choke. It'll never come off as soon as it should after an hour parking (I assume that's how long you need in the Playboy mansion ), the engine will still be hot and require no choke, but the electric heater element controlling the choke will have cooled off and will take some time to heat up again, and will run too rich in that time. Does your choke get a proper 12V? Most people including me at one point in time have looked around the engine room for a ignition +, and found it at the coil, but often that's only 9V, not enough to let the choke come off fast enough. Also make sure your choke is properly adjusted, as described in my book (sorry) the choke has to be as lean as possible while still providing decent cold starting, trial and error testing needed.

Second suggestion if it's only one puff of black smoke, could your fuel bowl needles be leaking slowly? At normal running, the fuel is used faster than the leak introduces it, when stopped it leaks until the pressure in the fuel line is gone.

Thirdly, if it's puffing black smoke all the time (and your mileage suggests it) it's too rich constantly, which the cold engine likes, but the warm engine does not. Full details on how to adjust this in my book (sorry), but also check if power valve is blown or more likely hardened and not functioning right. Easiest way is to press it against another same number power valve, they must move the same.

What I would do first? Write down how the choke is adjusted, move it to totally off, and see if it helps. Let us know...

Floats are too high or you have too much fuel pressure, or both.

Put a thermal barrier between the carb and the manifold.

If you don;t have one, the heat will rise through the carb and boil out the fuel. Since the only place it has to go is into the intake, it will severely flood the engine to the point of a cylinder collapsing.

The Webers are great for this but with them, they will blow the liquid fuel out like a volcanic eruption.

Mikael's second suggestion seems a good bet. You could pull the air filter and just watch the carb a while. I was amazed at one of mine showing signs of dampness and weeping. Float level too high?

If no sign of dampness, disconnect electric choke to eliminate that as a problem.

Good luck.

quote:

Originally posted by The Pope:
Mikael's second suggestion seems a good bet. You could pull the air filter and just watch the carb a while. I was amazed at one of mine showing signs of dampness and weeping. Float level too high?

If no sign of dampness, disconnect electric choke to eliminate that as a problem.

Good luck.

On a hot day after a Pantera has been run for a long time, it can actually boil the fuel in the carb after it is shut off. That boiling can overcome the needle valve on either the primary or secondary side. I know, because I have seen mine do it. An insulated carb spacer does help if you have the clearance for it. Rerouting the fuel line away from the top of the engine helps also.

I have the Wilson spacer that is worth a few horses. I ordered a new power valve. I had to lower the floats after a run in the mountians. The high alltitude and lower air pressure must have distorted a float. I replaced them with the phenolic solid floats. I'm betting it is the power valve too. The new one will be here in a day or 2 and I'll report back. Thanks Yall' Bill 1362

quote:

Originally posted by lastpushbutton:
I have the Wilson spacer that is worth a few horses. I ordered a new power valve. I had to lower the floats after a run in the mountians. The high alltitude and lower air pressure must have distorted a float. I replaced them with the phenolic solid floats. I'm betting it is the power valve too. The new one will be here in a day or 2 and I'll report back. Thanks Yall' Bill 1362

Don't forget to use a power valve "check valve". They do help. The failure rate on the PV's is alarming.

Good move on the solid floats and what JFFR says is very accurate.

The higher altitude will boil the fuel at a lower pressure and temperature.

Phenolitic insulator is all you can do and not to overly alarm you but the Holley needle and seats are crap too?

Make sure that you use a pressure regulator and set it under 7psi. What happens when the fuel "boils" is that pressure in the float bowl increases past the limit of the inlet valves.

At least with the regulator, that won't be true of the inlet pressure available.

...and stop doing those Pike's Peak hill climbs.

The angle is exceeding the limits of the bowl vents and spilling into the engine.

Gee-ze. Kids. Gotta' tell 'em everything?

I know my choke is working ok. It runs off the same 12 volt as the tach adapter. If I loose that power, the tach quits and it runs like shit. Just puffs black when restarting. It clears right out and goes back to running very strong. My power valve has shipped.

I replaced the power valve and noticed that the old one was not real tight. Then I fixed the problem when I lowered the front float a little. It was set too high. Thanks guys.. Bill1362