Carburetor Problem(s)

dmford · #1 (**permalink**) 09-16-2002, 02:27 PM

I had to replace the holley 650 double pumper base due to my over-tightening of it during assembly. I ordered the base and moved all the hardware over on it and installed it. It runs like crap. It idles fine and hard acceleration is fine but low to mid RPM steadystate operation sucks, it's like I shut off the key. I disconnected the secondarys and just ran it in two barrel mode and it still does it. I then just used the secondarys and it runs fine at low RPM steadystate. When it's having the problem, the jets (primary) are like a drippy faucet. there will be nothing then a big drip. At higher RPM you can see the jets working with a continuous mist. Is there any chance I have the wrong base (it looks the same and everything fits)? This Carb. worked fine prior to the base replacement.

Thanks,
Dave

Mr.Fixit · #2 (**permalink**) 09-16-2002, 02:39 PM

Perhaps the passage for the Power valve circuit is blocked. Perhaps you have blown the power valve diaphram.

mr0077 · #3 (**permalink**) 09-16-2002, 04:25 PM

Pull the base off and check the gasket placement...could you have flipped it or rotated it 180? It will fit 4 ways, not sure if all four will work.

Mongoose · #4 (**permalink**) 09-16-2002, 05:20 PM

Sure sounds like a vacuum leak to me. Try spraying around the base with WD-40 with the engine at an idle. If the RPM changes at all, you've found your leak.

dmford · #5 (**permalink**) 09-17-2002, 10:37 AM

Thank all you guys for the replys, They were thought provoking and led to the solution. I pulled off the base to check the gasket orientation and it was OK, it was rectangular so it could only go on two ways and it was symetric about the lateral axis so this one was idiot-proof, I found small slots in the secondary bores one the upper side of the throttle plates that the mains didn't have. I looked at the old base and the mains had a slot, so out came the Dremmel cutting wheel and after cutting some ridiculously sloppy slots in the main bores, I was out for my first decent ride that I've had in that car in 3 & 1/2 weeks. Runs better than ever!! Again thanks for the ideas!!!

Dave (I better find my hat eh)

Jack21 · #6 (**permalink**) 09-17-2002, 05:14 PM

Hmmmm. A new way to dial in Holleys? A new use for a Dremel tool? Guess I better find my hat, too.

Double Venom · #7 (**permalink**) 09-17-2002, 07:01 PM

How do you fix a Holley?

You replace it with Edelbrock!

DV