[oldmako]

Just installed a rebuilt holley 4160 600cfm on a F351 Windsor. The engine runs lousy at idle and at low rpm. It runs GREAT above about 2000-2500.

I have also:
1) Pulled the manifolds off and done a compressions test - all 130-135 psi
2) Replaced the rotor, cap, plugs, and wires.
3) Double-checked the timing to 10 BTDC

My question is this...

My carb came with a gasket with 4 holes which match the bottom of the carb. My edelbrock manifold only has 2 large rectangles for openings. The intake ate the centers of the gasket, and now all I have is the square and a small strip running fore and aft down the center of the two openings..

The carb has small channels machined in to it's base. I am wondering if the lack of a gasket between the primaries and the secondaries has got it all messed up?

The engine 1) idles rough, 2) will not start when warm unless you crack the throttle while cranking (or advance it and then close it prior to cranking), 3) hesitates and almost quits at low rpm when the throttle is barely opened, 4) idles very very high (like 1600) after a 3-4 minute WOT run, and in general runs like crap unless it's WFO. I feel as tho I'm driving a funny car....only it's a boat.

I can feel and hear the secondaries as they open and close, the linkage is free and clear, and my fuel is new and clean.

ANy suggestions?

 

[NXS]

Check the float levels. Set the idle mixture screws(1.5-2.5 turns out...the more out the more fuel)

If that doesn't work look at the power valve.

 

[oldmako]

The shop I bought the carb from says that they "bench flow test" all of them before they go out. But, I'm having so many problems that I'm starting to wonder. Yesterday the seconday float got stuck and the thing shot fuel all over the carb...a lil mount st helens right on top of my intake! would have made a great fire thats for sure.

I'll look at the idle mixture ...thanks.

 

[NJLuke]

Set those Bowls!

The 4160 series holley carb can be quite a handful sometimes(have one...) Since it looks like you have a flooding problem you would want to first check your float bowl levels- DONT go screwing around with the two mixture screws, this will pretty much do nothing for ya. after running the engine in nuetral(e-brake on!) shut her down and pull the brass plugs on the passenger side of the carb. The fuel should just barely seap out over the threads- yours will prolly gush out, have a rag handy! If the bowls are too full, get a big slotted screwdriver and a 5/8 wrench. put the 5/8 wrench on the nut on top of the bowl and then break the brass screw loose with the driver. I think you turn the wrench left to lower the level and right to raise.(it's a shame...i did this like an hour ago and already forget.) Tighten back down the brass screw and recheck the levels! Good Luck! I still havent decided if I like this carb yet- we will see.
-Luke

 

[user151]

channels under carburetor

"The carb has small channels machined in to it's [throttle body] base. I am wondering if the lack of a gasket between the primaries and the secondaries has got it all messed up?"

Old thread, I know, but interesting question.
My answer (opinion): I doubt it. The channels connect the primaries and secondaries, which is the case with or without a gasket... see photos...