O.K. well here's the whole story... I've got a holley 600 vac secondaries(4160, #66's, 6.5 power valve)on my 305 (only mods really is the intake manifold, its a edel. performer) and well, my car wasn't idling right (surging at idle + and - about 300 rpm) and seemed to be lacking power, so I'm like ok, something must be dirty and my power valve is dead, so I go get a new power valve, put it in (my old one seemed ok, but I put the new one in anyway) and I try to start my car and its just cranking. So after my battery is half dead I'm holding the gas half way down, it fires and runs REALLY crappy and only runs if I hold the gas way down. I'm like WTF!??! So I put in the old power valve and it starts up like never before, idles perfectly and I think the secondaries are working because it seems to have a hell of a lot of power now. Now when I hit the gas hard it stumbles but after that the power hits hard.... I didn't get a chance to check my float levels (its night time out). Could my float levels be too high or am I running rich or what? I can't figure it out I'm just tired as hell right now... also what could have been the problem with the new power valve, and why all of a sudden is the car idling right? Sorry if I sound all stupid and demented, I'm just really blah right now.

:lala: :lala: :lala:

 

Carbs are tricky things. Easy to screw them up. If it's running good now- stop touching it. A full-throttle stumble is pretty common with an out-of-the-box Holley. Try swapping your accelerator pump squirter to a #31 (#25 is stock) and I bet your stumble goes away. It's the metal part that the 2 little jets of fuel squirt out of when you open the throttle. It's inside the choke horn, between the primary venturis. It's held on by a single large phillips head screw.

When putting the new one on remember that there is a gasket both under the squirter itself and a slightly different tapered gasket under the screw head where it contacts the squirter. Basically the squirter is "sandwiched" beteen the main body and the screw head by 2 gaskets. These gaskets make sure all of the fuel actually comes out of the squirter nozzles and doesn't seep past places where it shouldn't, not helping to get the car accelerated when the throttles are opened quickly.

 

Well I fixed the stumble, IT USUALLY HELPS IF YOU GET THE LEVER FOR THE ACCELORATOR PUMP ON!!!!!!!!!! OMG I noticed that (while i was just aat a gas station so im like ok pull off the fuel bowl put it back on, now the fuel tube is leaking gas... I swear everytime I pull off the bowl they rip/break, so I made 2 o'rings out of these 2 rubber grommets I had laying around my car... omfg I'm getting FI when I get around to it

 

The nice thing about a Holley is that you can actually fix it with a ROCK...or two rubber grommets that you have laying in your car. Try that with FI... LOL

 

HAH, maybe I can smash it with a rock I'd like to get a 650 dp and get rid of this crap, I've heard from people that this carb sucks (holley 4160, 600cfm, vac sec.). Plus having vaccuum secondaries isn't helping since I have a 5 speed

BTW do any of you have suggestions as to replacing those o'rings with something more durable?

 

The only cure is replace the o'rings every time you remove the float bowls. You can buy them in pkg quantities of 10 from companies such as AED or Barry Grant. AED 10qty Part Number : 6344X....or you can do like I do...go to a place like Home Depot and buy Neoprene O-rings dirt cheap. They're nothing special from Holley. BTW ...home depot also has some nice hard plastic washers that do just nicely for the float bowl screw gaskets.

Carburator suggstions...yeah. The carb you have is not the best. You would be better off with something like a 650 DP #4777C. It mayl need some tuning for street use though. DP's out of the box are jetted too rich on the Primary and you have to do some accelerator pump cam and nozzle tuning. The Pink cam is an awefull cam for the street or anything else for that matter except a Full on Drag car. Too much fuel and all at the wrong time as I've explained in another post. A much better combo is a Blue cam in the #2 hole on both Primary and Secondary sides. Then play with Primary shooter size.

Going down two sizes on the Primary jets will usually put you in the Ballpark. Leave the Secondary jetting alone at first. Try it first of course.

 

Chickenman's got a good idea there. I have noticed that AED has been putting these hard plastic gaskets in their kits lately for the bowl screws, intlet valves, etc. instead of the usual paper gaskets. Having rebuilt a LOT of carbs I was sceptical at first- thought they wouldn't seal up very well. They do. Over and over again. Made me wonder why nobody had thought of this before.