Carb gurus

[greygoose]

I have a holly 4106 600cm carb,that continues to drip fuel in the bowl which,then leaks out at the gasket between the carb and manifold.There is a pic of the carb and it's the one on the left.How do I fix this problem?

[mrh33916]

4 things could cause that,

1 Fuel pressure in excess of 7 PSI

2 Float set too high

3 Defective needle and seat assembly or o ring

4 Trash in needle and seat assembly

5 Bad float inside carb.

The float probably wouldn't be bad, I would expect it to be 1,2,3 or 4. Have you ever been inside the carb?

[69C10@16]

Please note that only four things can cause this but five are listed. lol

[monte0185]

I agree with MRH on the 5 things. Has the carb sat at all? If so it needs rebuilt. Not sure why but holleys do not like to be shelved for any amount of time. Do you have a PAPER filter? Not one of those clear glass filters with the plastic screen. Those will destroy a holley quick fast and in a hurry. Also how is your float set? With the truck pretty level you should be able to pull the sight plug and bump the truck and have just a dribble of fuel come out. Well theres my .03 or .04 cents anyways. hope it helps.

[greygoose]

Thanks guys,the carb is new,that all that I know about carbs.I know that my gas gauge is not right,would that also be a sign?And the filter is the black,like the material is like a thin piece of cardboard.

[americanmusc1e]

my 4160 holley does the same thing sometimes. I have called holley and taken it apart and never found the problem. most of the time if you tap on the bowl with a screwdriver it will go away. one time i had to drain the bowl by loosening the bolts to make it go away.

[Tony]

I used to have a small business modifying Holley's for oddball applications like inline 6's.Flooding was always the things mentioned above.
Doing a SBC recently and having some flooding issues with an Edelbrock carb I got to checking fuel pressure.I tried two fuel pumps,one a new Delco pump and a Airtex rebuilt.The Delco had in excess of 9 psi and the Airtex about 7 psi on a warmed up running engine.When the engine was shut off the pressure rose a little higher for a short time before it dropped off.A simple Holley fuel pressure regulator and wrapping the fuel line with an insulating material solved the problem for me.But if you're having excessive fuel pressure from heat soak after shutting down then a regulator with a return might be required. And make sure the fuel line isn't routed closly to the hot engine and insulate it if necessary.

[greygoose]

Thanks guys,would a regulator from any part store do the job?

[mrh33916]

You need a regulator that will adjust fuel pressure from @4-9psi. If you don't already have one I would first buy a Combination vacum/pressure gauge available at most parts stores and check the pressure to see if that is the problem. You can also use that gauge to set the air/fuel mixture on the carb.

[greygoose]

Ok guys I got the pressure regulator from autozone,and it worked fine,no leak.But today when I started it up it ran ruff and then it died,so I took off the fuel out side and turned it over but it wasn't getting any gas.So I took it back off and it run good,but now I have the leak again.By the way the fuel pressure regulator was a round looking thing with a dial knob on it and it went up to five psi,I think it was made by spectrum or something like that,it was 26 bucks,the guy at the store went over by the dress-up kit stuff and got it.So,is it just a cheap one or is there something else wrong with it?

[greygoose]

And another thing that you guys maybe able to help me out with.Normal driving is fine,but when I step on the peddle hard there is a hesitation before it kicks in,almost like it's goes silent or like a drop off or something.What is that and how do I fix it?

[us111]

HELLO,different carb (edel 1406)but running that same regulator that works just fine.anything above 3.5 psi and mine does the same thing,leaks,runs like
crap etc.

[60ratrod]

that's weird. my old 4160 never liked anything over 4.5 psi. as for the hesitation, it sounds like you have either too much advance or a lean condition. so you probably need one to two sizes richer on your jets. start with the next richer jet, and drive it. if you still get the hesitation, go to the next. my edelbrock had the same hesitation and i fixed it by richening the metering system(rods and jets).

[americanmusc1e]

Originally Posted by greygoose

Ok guys I got the pressure regulator from autozone,and it worked fine,no leak.But today when I started it up it ran ruff and then it died,so I took off the fuel out side and turned it over but it wasn't getting any gas.So I took it back off and it run good,but now I have the leak again.By the way the fuel pressure regulator was a round looking thing with a dial knob on it and it went up to five psi,I think it was made by spectrum or something like that,it was 26 bucks,the guy at the store went over by the dress-up kit stuff and got it.So,is it just a cheap one or is there something else wrong with it?

I also have a spectre fuel pressure regulator that doesen't work right, not sure if it ever has

[SSC's76]

To be honest I'd say the float level needs to come down on the back a tad. The cheap fuel pressure regulators work ok there not great. A return style regulator would be more ideal since instead of having the fuel pressure dead headed it routes the fuel back to the tank this makes electric pumps very happy and keeps mechnical pumps from weeping. This is the whole reason the 3 port return sytle pump was invented. but yeah Ive got my electric pump dead headed on my truck works real well for full on high rpm flow but driving on the street it can be picky.

EDIT: Just courious how much vacuum your engine is pulling? Ive seen cases where the engine is pulling soo much vacuum it will pull fuel from there just becasue the vaccum is very high. Slightly opening the rear throttle blades up solved this problem thats why on the back side I always flip the adjustment screw around so it can be adjusted from the top of the carb. A small adjustment there might also help with the bog if its a lean bog

[crazy longhorn]

I dont know how new the carb is, but I have "fixed" the fuel drip problem by installing new bowl & metering block gaskets in a used Holley carb. most of the Holleys I have run will tollerate around 8psi on the pump, & not upset the needle(assuming it seals properly).....5.5 -6psi on a stock pump wont jack with them. The edelbrock carb is more sensative to fuel pressure(5-5.5 psi). best of luck,crazyL