RPM Drop From Nuetral to Gear

Mattax said
A little history of why they had so many leakers at that time in is in this archived thread about power valves from the old Innovate forum.
Go down about 1/4 way down the page to post #9 by "Tuner"

WOW Never knew that............

mopowers said
OK I think I'm getting somewhere. I swapped out the PV for a plug in the primaries and disconnected the PCV (and plugged the port). It fired right up and seems to run A LOT cleaner......................................... When looking at the PV on the bench, it appears to be fine. I tested it with a vac pump and it worked fine. I'm thinking maybe the gasket was leaking?

The thing that causes a PV to run rich at idle is not that it's open or closed, unless the engine / throttles are fast enough to be pulling fuel from the main venturies.

What DOES happen is that the DIAPHRAGM leaks, either a hole or improperly crimped, or over-tightened and damaged the valve. Realize that you have fuel sitting on one side of the diaphragm and "high vacuum" on the other. It does not take much of a hole to pull fuel through there.

You won't see this.......only be able to confirm by swapping valves.

There is the possibility that the gasket is leaking, but these are not usually a problem

DO NOT overtighten.