[Gaz64]

It sounds like you have two carbs assembled by the same tech who left the power valve protection ball springs out on assembly?

I can't see anywhere that QFT does not use the spring like Holley does.

Clearly the spring keeps the ball open in both directions for normal valve operation.

QFTs instructions:

1. Remove throttle body from main body
2. Locate the power valve vacuum passage (note: small hole next to the center
throttle body screws pri. & sec.)
3. Check the drill collar height this should be 9/32” of the drill point exposed)
4. On the main body surface of the throttle body, drill the P.V. vacuum passage until
the drill collar contacts the gasket surface.
5. Remove all chips and deburr if necessary
6. Install the spring provided with the large end of the spring at the bottom.
7. Install the check ball.
8. Position the new seat in the hole and lightly tap it with a drift and small punch until it
is flush with the gasket surface.
9. Reinstall the throttle body.
P/N 99-18
© Quick Fuel Technology 2012