Hi all, Rebuilt my Holley 94 with master kit from Vintage speed. Replaced .057 jets (not stock) with .053 and the power valve went from 8.5(leaking) to a stock 7.5....carb runs real well....but after running a while occasionally it starts to whistle???
I put a section of radiator hose to my ear and it seems to be coming from under the bowl area, all gaskets seem o.k., no leaks of fuel.
Could this be the vaccume pull on the power valve?
Ed

 

I don't see any way it could be the power valve.
I would expect it to be a vac leak on the base gasket.
Try to pinpoint the location as much as possible and then squirt some oil on the likely spot. It should change the sound as it sucks the oil in if you hit the right spot.

 

I'd bet the p.v. is sticking out too far and preventing the throttle section from seating against the bowl section. Without a gasket between the two sections, put them together -- they should fit together tightly. If the p.v. is sticking out too far, you'll feel it rocking.

 

I think I will take it back apart and check the gasket\seal for the power vaule under the bowl. There was supposed to be a leakproof nylon seal supplied but was not in the kit...I may have to go ahead and order another seal, the stock style gasket provided was fairly thick. The carb bodies felt good when seated together but the pv seal may just be too thick???

 

That would have the same effect if the washer is too fat. I'm guessing it is a red fibre washer? With sort of a triangular center hole?

If you don't want to wait, take the PV down to a good hardware store (True Value, etc.) that has an assortment of copper washers, and find one that fits. Best to anneal it first, which is easy: heat it up with a propane torch til it starts discoloring, then let it cool down. It makes it softer.