We do know the zjautoparts was also modeled after the Rochester Quadrajet carburetor

[zjautoparts Lee]

 We do know the zjautoparts was also modeled after the Rochester Quadrajet carburetor with sizable secondaries and small primaries. Secondary operation is similar to the Quadrajet with mechanical function and vacuum-operated air valves, which make the transition from primary to secondary crisp and smooth when properly tuned. When secondaries are fully opened, overwhelming manifold vacuum opens the air valves.

Needle Valve

With a spring-loaded clip at one end and a tapered rubber tip at the other, the needle valve works in unison with the float. The needle valve also works with the seat assembly, which is simply a screw-in brass bolt – drilled to take the shape of the rubber tipped needle. The seat assembly is the end of the fuel line, where fuel is waiting to enter the chamber. When the chamber is full, the rubber-tipped needle is pressed into the seat, preventing fuel from overflowing the chamber.

Note: Different sized needles and seat assemblies are available for specialty requirements like racing and altitude corrections – the fuel requirement is lower at higher altitudes due to a lower atmospheric pressure.

You want to set the float height so the bike runs on the exact amount of fuel it needs – no more, no less. To set the float height, it is first necessary to determine the current settings. This can be done in two ways: by using an external measuring pipe, or by measuring the physical height of the float above the Main nozzle.