Thread: New Problem - Fuel Coming Out of Front Fuel Vent

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Well, I went out and messed witht the carb a little more. This time, after loosening and tightening the bowl in hopes of shaking loose the float, something changed. Fuel no longer came out of the vent, but it still ran down into the carb when the fuel pump came on.

I didn't try to start it. I wanted to ask you guys what you thought first.

Since I have a bit of a fever, switching on the Edelbrock from my other ride will have to wait a day or two.

Thanks again for all the great advice, everyone. It sounds like I need to rebuild this bad boy. I don't know squat about the internals of a carb, but I am here to learn!

before you start it CHECK YOUR OIL!!! IF YOU SMELL GAS IN THE OIL CHANGE IT BEFORE YOU START MOTOR. YOU CAN WIPE OUT CAM BEARINGS VERY EASY BECAUSE THE FUEL NO ONLY DILUTES THE OIL & DECREASES LUBRICATION ABILITY BUT WILL WASH OUT ASSEMBLY / CAM LUBE REAL QUICK & YOU CAN SCREW UP NEW MOTOR BIG TIME. 31 5w

I would also take all the plugs out of the engine and spin it over to pump out an excess gas out of the cylinders.
Make sure you disconnect the coil wire from the distributor.

It sounds like a possible sticking float, or sinking. The needles might not be in the seats properly. They might have some pieces of dirt or something on them keeping them from closing.

I had a really old and troublesome 750 and one way I would dislodge a stuck float would be to open up the sight plug and lightly jiggle it with a small screwdriver. Be very careful doing this on a hot engine with the bowls overfull. Boiling gas can be dangerous.

Something else that hasn't been mentioned is your fuel pressure. You might just be blowing the needles off of their seats with excessive pressure.

Originally Posted by erik erikson

I would also take all the plugs out of the engine and spin it over to pump out an excess gas out of the cylinders.
Make sure you disconnect the coil wire from the distributor.

I assume that the fuel that dripped into the intake might have found its way into a few of the cylinders?

Also, on the fuel in the oil thing: Everything back there smells like gas right now, so I don't know if I could detect it in the oil specifically. I just put new oil in before the intake went on and planned to replace it after the first startup because of the coolant that got in the system before I tore it down. I guess I might as well change it now...

Originally Posted by pelligrini

It sounds like a possible sticking float, or sinking. The needles might not be in the seats properly. They might have some pieces of dirt or something on them keeping them from closing.

I had a really old and troublesome 750 and one way I would dislodge a stuck float would be to open up the sight plug and lightly jiggle it with a small screwdriver. Be very careful doing this on a hot engine with the bowls overfull. Boiling gas can be dangerous.

Something else that hasn't been mentioned is your fuel pressure. You might just be blowing the needles off of their seats with excessive pressure.

Thanks for the advice. The fuel pressure is right at 6lbs, and I have been told that is right.

Is the sight plug covered with a screw? I need to learn more about carbs, that's for sure. Tapping it with a hammer didn't seem to move the float (if that is the problem), so I will just take it all off and put my Edelbrock 650 on while it is torn down and rebuilt.

What's a rebuild kit cost these days?

Originally Posted by 31 5w

before you start it CHECK YOUR OIL!!! IF YOU SMELL GAS IN THE OIL CHANGE IT BEFORE YOU START MOTOR. YOU CAN WIPE OUT CAM BEARINGS VERY EASY BECAUSE THE FUEL NO ONLY DILUTES THE OIL & DECREASES LUBRICATION ABILITY BUT WILL WASH OUT ASSEMBLY / CAM LUBE REAL QUICK & YOU CAN SCREW UP NEW MOTOR BIG TIME. 31 5w

This motor has been run for a total of 10 minutes, so is cam lube still an issue?

I'll check it, though. Thanks!

Originally Posted by Saxman

Is the sight plug covered with a screw?

What's a rebuild kit cost these days?

Yea, the plugs are on the sides and they look like a flat screw.

You might just have the levels set up too high. See Poncho's earlier post on how to adjust them.

There's a whole lot of info on Holley's tech library.
http://www.holley.com/TechService/Library.asp

Last time I got a rebuild kit for my old 4010 I think it was around $40-50.

Summit or Jegs can give you a more accurate price.