Holley Carb Help

[fng]

After driving only 36 miles my new Holley 650 has started to leak. It has a drip from the right side from the bottom of the vacuum secondary rod. The truck has had problems of "running on" or not dieing after the switch is placed to the off position, which caused a couple of backfires. Is it possible that the diaphragm has suffered from this? Thanks in advance for any help.
P.S. I'm asking BEFORE I tear into this so at least I'll have some Idea of where to start, it's a PITA to get to now that I've got the truck built....

[LuckyPabst]

It's been a while since I've been in a Holley but I know backfires would kill the power valve. But now that I have that in writing it's occured to me that I think Holley started putting the power valve anti-backfire thing in their aftermarket carbs.

I would check also that the float bowls are snug and the fuel crossover pipe isn't leaking where it enters the float bowls.

The secondary diaphragm should have atmospheric pressure on one side and engine vacuum from the venturi area on the other and even if it were ruptured, you shouldn't have fuel dripping.

Chris

[anderpig]

sounds like the float level is to high

[vrod02]

power booster? Its a dio that tend to blow from backfire. Holleys are a pain in the arse,esp dialing the floats. I switched to edel/carters. Best carb IMHO. Although holleys run down the track well if you like to tinker.