stalling, 4150 breather tube spewing fuel

[ratonabike]

ok i had this prob awhile back when i rebuilt my HP4150... fuel would pour out of the breather tubes while the engine would starve for fuel and die... i screwed down (up?) my float bowl level adjusters until my floats closed earlier, and that seemed to stop the problem. pulling my level screws out to check on my gas level, and they were just right it seemed (fuel just barely pouring out of the checking holes), though my adjusters were set almost completely down (pulling the valves up and closed), with almost no adjustment left in them. now my car started to stall out of nowhere again (always at idle in traffic), and after pulling my airbox, and running the car for about 15 minutes, i would rev it high for a bit and back off to idle, and i could see the fuel pouring out of the breather tube all of a sudden (only the primary breather this time), stalling the motor. I checked my float level and it seemed just right, so i ran the car again and put another round into the adjuster, lowering the float level, and the car seemed to run fine, with no fuel spewing out of the breather, but my float level seems too low now (not spilling out of the level hole), and i was too nervous to take her out into traffic and stall blocking the street again (slightly embarrassing to say the least, though it was pretty cool when two really hot girls jumped to help me to push my car out of the way.. hah)... i have very little experience with Holley's, still on a learning curve... wondering if the rebuild parts i used (the float valves specifically), were possibly the wrong ones, though they look the same length, though the numbers don't match the original. Any ideas why i would have fuel spewing out of the breather tubes, thereby stalling my car? my fuel pressure seems pretty consistent, at around 7 psi at idle, and 6-1/2 psi at higher revs. thanx (to whoever is still out on this board)

[RichSchmidt]

Holley carbs are very sensitive to excessive fuel pressure,and the needle and seats is very sensitive to dirt.Mechanical fuel pumps are always a source of drama with a Holley carb since typically they build way too much pressure when engine load changed from high load to low load.You actually should run a fuel pressure regualtor set at 4.5 to 5.5 psi with a Holley carb no matter what fuel pump you use.Another issue is pressure in the gas tank.If your tank isnt vented properly which would be the case if all your factory vent tubes were plugged off and your pollution canister were removed,then you could have well more then the maximum 8psi building up in your tank when the fuel expands from heat and movement.This would cause your carb to flood over.Dirt in the needle and seat could be a culprit as well as a nicked or damaged needle and seat.Another issue could be if the lever on the float is bent or damged.Unlike some carbs where the float adjustment is made by bending the float arm,on a Holley you thread the needle and seat downward.If you ran the adjustment down too far you could have bent the tab on the float that normally pushes on the needle valve.You can check this by taking the float bowl off,holding it up and setting the float adjustment so that the top of the float is level with the top of the float bowl(not hitting it,LEVEL WITH IT)at that point you should be able to remove the nut and screw off the adjuster and see at least 2 or 3 threads sticking out of the top of the bowl.If you have less then that,then you need to bend the small tab on the float arm to compensate intil you get the correct situation.

Good luck.

[ratonabike]

rich thanks so much for the info! the first thing i'll do is dial my fuel pressure regulator down like u said. and my fuel cell isn't a prob, i'm actually running a bit too big of a vent tube in it, so that's not an issue. but it sounds like i definitely probably bent the tab on my float bowls like u said, as i threaded the adjusters almost completely down. i'll pull my bowls and check it like you said. thanks!!!