Thread: Flooding

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I have an 830 annular boost Holley carb which is spilling fuel out of the left side annular booster at around 2000 rpm with the tranny in neutral. So much so that I went through a half tank of fuel within a 20 mile drive (@ 1.68 per liter) and it runs real crappy.

I replaced the power valve, shot carb cleaner through the mettering block and carb mating area, lowered the needle and seat, and still no good. No fuel is pouring out of the side inspection screw hole when the motor isn't running but the fuel pump is on.

It was running great a few days ago, now this. What might it be? Could the fuel pump suddenly be putting out too much fuel pressure at 2000 rpm?

BTW, I would highly recommend wearing safety glasses when spraying carb cleaner with that tiny tube stuck partially into the channels of the metering block. Don't ask how I know.

Ok, I just replaced the front needle and seat, and the problem remains. The left front booster is spilling fuel into the carb.

Has the carb worked weel before and then all of a sudden started thisor did you change pumps?

If it worked before then all of a sudden started it almost has to be in the needle and seat area. check the O-rings around the seat barrel to see if they are letting fuel bypass the seat. check the seat to see if the neoprene point is bad, or if there is a nick if it is brass. check the float for saturation or full of fuel if it is hollow brass.

my 2c worth.
John

You didn't by chance have a jet fall out did you? To have fuel running out of only one booster means you are dealing with one jet.

Originally Posted by 41willys

Has the carb worked weel before and then all of a sudden started thisor did you change pumps?

If it worked before then all of a sudden started it almost has to be in the needle and seat area. check the O-rings around the seat barrel to see if they are letting fuel bypass the seat. check the seat to see if the neoprene point is bad, or if there is a nick if it is brass. check the float for saturation or full of fuel if it is hollow brass.

my 2c worth.
John

It started all of a sudden, the fuel pump has not been changed. I just installed a brand new needle and seat, but I forgot to check the float, I 'll do that now, and thanks.

K, both jets were tight and both were 75s. The float is plastic and it is good as new. No fuel in it and I double checked by holding it under water and giving it a squeese, no bubbles.
What next?

Boy, that a good one. the only way fuel can get to the booster is either through the jet or past the power valve. You said the gas was coming out of the sight glass. That has to mean th bowl is over filling so were are back to the fuel inlet. I know you said the float looks good but sometimes they will fool you. You say it is plastic. I asume you mean molded dense nitrophyl(sp) and not hollow. I have never seen a hollow plastic float but then I've never seen a lot of things.
If it is nitrophyl they do sometime get saturated and heavier than fuel and will force it out the vent tube and out the booster. If you are in doubt let the float air dry out for a while and try it again.
John

No, the gas is not coming out of the sight hole. I have let the float air dry and I bought new gaskets and will try that.

No good. I even installed a new power valve gasket just incase. I also made sure all the passages in the metering block were clear once again.

Just as I was about to sit down here and post, I remembered inserting a big screw driver into the butterflies while checking compression in order to have the air get to the pistons. I thought I had been careful when inserting but maybe that one butterfly is bent. Strange thing though, I drove it after checking compression and it ran wonderfully for several days.

Last thing I had done before this all happened is I had my headers welded.

Bottom line, that left front Booster is flowing fuel.

The butterflies shut perfectly. I blew carb cleaner through all the channels once again ensuring that the air ways were open, I have no idea what to do next.
I have a new 770 vacuum secondaries laying there, but that's not the answer. Maybe I should swap the front metering block from that one.

K, I phoned Holley and they suggested that I swap metering blocks from the rear to the front. I did that, and now it runs perfect, but the defective metering block is on the rear, however it is only used during full throttle so how will I ever know if it works or not, hahaha!

Holley tech figured it had to do with my air passages being plugged, but damn, I checked and rechecked those puppies 10 times, each channel.

Originally Posted by TyphoonZR

K, I phoned Holley and they suggested that I swap metering blocks from the rear to the front. I did that, and now it runs perfect, but the defective metering block is on the rear, however it is only used during full throttle so how will I ever know if it works or not, hahaha!

Holley tech figured it had to do with my air passages being plugged, but damn, I checked and rechecked those puppies 10 times, each channel.

Very good. Glad you got it figured out.