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carb problems

1K views 5 replies 4 participants last post by  johnsongrass1 
#1 ·
I just rebuilt a holley 650 double pumper. The carb was put on a shelf years ago with fuel in the bowls. I pulled the bowls and metering plates and soaked them over night in parts cleaner. The main body didn't look bad so just a cleaning with carb cleaner.
I put it back together with all new parts and put it on the car. On the primarys my the bowl level is to high and I have fuel dripping into the intake.
My thoughts were bad needle valve or bad o-ring on needle valve. could this be right? I was just thinking I may have gone the wrong way with the float level adjustment I turned it in does that raise or lower the level in the bowl? :embarrass
Thanks for any help
Dave
 
#2 ·
I've got my 750 DP sitting on my lap right now. The idea with Holleys is to remove the sight screw (on the side of the float bowl) and adjust the 5/8 hex nut (after unlocking it with the slot head screw) on the top of the float bowl. Clock wise to lower the float level or CCW to raise the float level until fuel just touches the bottom of the sight hole without running out. Of course, you're doing this with the engine running. Be careful, if fuel is running out of the sight hole you may want to shut off the engine and lower it before starting it again, you might start a fire with fuel spraying all over the place. Here' s a website that I found pretty good for explaining how to tune a Holley.

http://www.bob2000.com/carb.html

I had a Holley on a past vehicle and I didn't really appreciate what it could do. These are a very tuneable carb that can do wonders for you if you know how to properly tune them. I'm just starting to understand how to adjust them and I can see myself spending a lot of time getting to understand every aspect of these devices.
 
#5 ·
thanks for the reply. the fuel preasure is only five psi. The needle valves are new. I haven't had a chance to check anything. I'm just looking for other points of view. I may have nicked the o-ring on the needle valve I didn't put any lube on them before putting them in. I'll probably get to it on saturday.
Thanks
Dave
 
#6 ·
IF you turn the float in you must wait for the engine to burn off the extra fuel in the bowl. If you don't, The volume of the float will over flow the bowl and fuel will run out the site plug. Instead of waiting on the engine to burn fuel you can set the floats really low then unscrew the needle to bring the fuel levels where they need to be.
 
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