Many carburetors on the market today use needle valves. The needle jet is actually a long, thin rod that is tapered at the bottom, placed in the inlet side of the main jets. This rod responds to the movement of the throttle. As it is lifted out of the main jet, more fuel is allowed to flow in; conversely, as it is dropped in the jet, the fuel flow lessens.
Needle valves play an important role in regulating the amount of a substance released by flow, pressure and direction. Needle valves also have the ability to shut off the flow entirely. Needle valves resemble globe valves in function and design except the needle valve has a point rather than a disc at the end of … Read more