Holley carb question

[76TA428]

I've got a 750 dp on a 428. I have 2 -8 lines coming from my regulator to each fuel inlet. It seems that the carb is flooding the engine and not allowing me to give it any throttle. I rebuilt it recently with an aed kit. The floats look to be leak free and are contacting the needle but its still overloading the bowls and if I leave the pump on too long I get a nice overflow of fuel out the vent tubes, even when the engine is running. I have 73 jets in the primary and 80's in the secondary. 5.5 powervalve. any suggestions?

[76TA428]

I've got a 750 dp on a 428. I have 2 -8 lines coming from my regulator to each fuel inlet. It seems that the carb is flooding the engine and not allowing me to give it any throttle. I rebuilt it recently with an aed kit. The floats look to be leak free and are contacting the needle but its still overloading the bowls and if I leave the pump on too long I get a nice overflow of fuel out the vent tubes, even when the engine is running. I have 73 jets in the primary and 80's in the secondary. 5.5 powervalve. any suggestions?

[tikiklubracing]

Sounds like it needs the floats adj. down. http://forums.performanceyears.com/groupee_common/emoticons/icon_smile.gif

[RPM]

check fuel pressure

[Tom Vaught]

Run only original Holley needles and seats.

Set the fuel pressure to 6-7 psi max.

Tom Vaught

[76TA428]

Primary float is set to where its level when it engages the needle. secondary is set a little higher. The regulator I have is adjustable from 4.5 to 9 psi. Its set all the way open at 4.5 psi. I'm thinking since the needle and seats came with the kit they might not be working right (cheap). Would it be worth my time to change the floats along with some new needle and seats? What size shoud I go with?
I forgot to mention the fact that after I have to shut it off from overflowing fuel I normally have a nice backfire or fire inside the carb. I'm just guessing its from unused fuel getting ignited. The timing is set right

[fasteddy]

The floats are probably fine--just replace the needle and seat in both bowls and make final adjustments with the pump on using the site holes. If you have the bowls off, turn the needle assembly clockwise until the the top of the float is resting just above level (lower than normal running level. This will allow you to back out the needle assembly for the correct wet setting--just almost running out of the site hole.

[68GTOConv]

My HP4150 (950cfm) was flooding the secondary barrels which prompted me to rebuild the carb. My problem was a needle/seat, which I bet is yours as well. It's also possible that the float is either bad, or it's adjusted too high.

Any of those things will allow tons of fuel to go through when it shouldn't. Not that it would cause the problem you've described, but while you have it apart you might want to put in new power valves since you mentioned backfires. Some Holley carbs have protection against ruining the power valve, but some don't.

Mike M

[76TA428]

Now I'm thinking its a stuck valve or a bad valve. Going to do a compression check today or tomorrow. Rebuilt carb with a holley performance rebuild kit and its still backfiring and catching fire in the carb. Its either the valve or the carb has a leak somewhere, I'm thinking around the ckoke lever since gas accumulates beneath it. If its neither then it could be not enough voltage at the hei. This has been one ongoing struggle after another but I guess thats part of the package.

edit: Thinking more about it, could my problems be caused by my rockers being too tight? Reinstalled the stock hardware on the stock pressed in studs, non adjustable.

[samssuperpro]

One problem you have is the lines going to the carb need to be -6 Then take a vacuum gauge and see what kind of vac. you have with the car in drive. Sounds like your powervales are staying open either put a 45 or a block off in it. Let me know if that works for you.

[Lerry: The Body Ventura..]

Maybe your gauge is shot...