VW Carburetor Idle Jet - Select Size - Weber IDF DCNF - EMPI HPMX

The EMPI IDF, DCNF & HPMX Carburetor Replacement Idle Jets are sold individually in sizes ranging from 0.40 to 0.70. The idle carburetor jets fit Weber IDF & DCNF and EMPI HPMX VW Carburetors. Idle jets allow you to dial in your carburetor for your altitude, engine size or the quality of fuel that you have available. Your carburetor runs on the idle jet from idle to roughly 2500 RPM. Most of the time that you are driving, you are running on the idle jet. If your engine is otherwise well tuned (the timing is correctly set, the valves are adjusted, etc) and the carburetor is mis-firing below 2500 RPM there is a good chance that your idle jet is too small, your engine is running lean and should be swapped out for a larger size. Conversely, if the engine doesn't run well or seems bogged down, the idle jet is probably too large and the engine is running rich and the idle jet should be changed out for a smaller one. Running too lean can cause your engine to over heat and can burn a hole in a piston or valve. Running too rich wastes fuel (lower MPG) and can actually cause premature engine wear as it can wash away the oil lubricating the piston and cylinder. Spending the time to properly dial in your carburetor is well worthwhile as it helps ensure a cool running, fuel efficient engine.