I just put a freshly rebuilt old holley vac secondary on a car and noticed gas continues to dribble into the intake for a bit after the engine is shut down. What is the easiest cleanest way to set the floats properly on the car without spilling gas all over a clean engine? I have a mechanical fuel pump, thanks.
If it has a sight plug on the side just remove it and set the float level right at the point where gas just dribbles out the hole when you lean on the fender.
That's my problem, this carb has no sight plugs. I know how to use the adjusting nut and lock screw just need a tip or trick for these carbs with no sight plugs, thanks!
I guess just lower it one turn. You might need to pull the bowl and see how much each turn effects the float level.
Do you have a heat plate under your carb?
No heat plate. I was going to try make a few adjustments and have it to the point where I can see it dribbling down the carb throat while the engine is idling but then it stops dribbling almost as soon as the engine is shut off. Does that sound close enough?
What model number holley do you have? I have never came across a holley that did not have sight plugs if it has external adjustable float adjustments. The only float bowls that I know of that does not have sight plugs are the side hung float bowls non adjustable type which is actually adjusted on the inside by adjusting the tang on the float arm itself.
Why holley calls them non adjustable is another story but they are the only ones I have seen with no sight plugs. I had this problem like you have with fuel dribbling out the boosters and mine did not have the sight plugs. I got tired of taking the carb apart and trying to get the side hung floats to give the proper fuel level and the floats ended up almost at the bottom of the bowl to get correct level so I ditched them to never use again.
I changed out to center hung bowls and nothing else and they are adjusted just like holley says about the middle of the bowl and have never had any problems.
If your holley is a side hung fuel bowl type you can convert to a center hung float type with a fuel bowl change. From my experience the side hung bowl design is more picky with fuel pressure and float level setting then the center hung design if that is what you have. Hope you can post the numbers or a picture as that might help.
Fuel pressure needs to be no more then 7 psi as that also will cause the same problem your having.
No!!
You don't want it dribbling at all!
You could be running rich all the time and possibly fuel washing your cylinders.
You need to find the sweet spot.
A heat plate will help keep the fuel from boiling in the carb.
Thats what I figured its a side hung float fuel bowl. At least you have a secondary metering block on that carb. If I was you I would get a set of center hung float bowls and the floats etc and convert it if you have the funds. When I first got my holley 1850s 600cfm vacuum secondary carb it came with the non adjustable side hung floats and had nothing but trouble with not being able to check the fuel level cause the bowls don't have site plugs. The floats adjusted internal with a tang. I then got a set of externally adjustable fuel bowls and swapped out the parts minus the needle and seat assembly's and then put back together and I had to have the floats almost to the bottom of the bowl to keep it from dribbling fuel and being to high of fuel level and my fuel pressure was just fine. Changing out to a new needle and seat assembly never would fix it. i changed to the center hung bowls and adjusted the floats like they should work and never had any more problems like I did with the side hung bowls.
Here is a suggestion since you have your carb off take the bowls off and hold the bowl up and push up the float all the way to where its closed and blow through the fuel inlet tube and make sure that the needle and seat completely close. I once built a carb for my brother and it dribbled gas anywhere and no amount of adjustment would fix it. So i took it back apart and my dad showed me the trick of making sure your needle and seat completely seal shut when the float is at its highest point by blowing through the fuel inlet tube on the front and back making sure it seals.
I bent the tang to adjust and boom problem fixed. I don't know if you have the nitrophyl floats that has the tang on it or the one that does not. If you got the brass floats then they have the tang as well. One we have the numbers off the tower we hopefully can go further.
. On those carb.s, with the bowl off, I usually just adjust the float so that the top of it is horizontal when lifted up gently by hand until the float needle valve is closed... float can't be high enough to touch top of bowl when it's installed... but, as suggested above, make sure the needle and seat are in good condition so they seal off completely when closed... float level adjustment can be changed if carb. is shaken or banged around in transit/shipping and the delicate float mounting tang gets bent... some also have a little sheet metal baffle inside that can get shaken out of position and keep the float from going up or down... I once got a new $450 marine Holley for $150 because it was returned because it "didn't work"... the baffle merely came loose from improper assembly or rough handling and was jammed under the float bowl, preventing gas from entering...
. Also, make sure the power valve diaphragm isn't blown out and the power valve has the correct vacuum # for the cam spec.s/idle vacuum... as I recall, about a 10.5 valve for a stock mild engine... should be OK since carb. just rebuilt... depending on your cam size...
Holley specs a starting place of "Top of float level with top of bowl when held upside down"
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