Main Jet DGV, DFV, ICT EPC 120

OVERVIEW

Precision tuning is the heartbeat of a high-performing air-cooled engine, and the EMPI Main Jet for DGV, DFV, ICT, and EPC carburetors is the essential tool for dialing in your fuel-to-air ratio. When you are pushing your vintage Volkswagen to its limits, whether on a coastal cruise or a demanding mountain pass, the main jet controls the fuel flow during the primary cruising and high-speed circuits. This 120-sized jet is meticulously engineered to provide consistent fuel atomization, ensuring that your engine doesn''t suffer from the dreaded lean-out conditions that lead to overheating and potential internal damage. By swapping out your factory jets for these high-precision brass components, you gain the ability to compensate for modifications like performance camshafts, high-flow exhaust systems, or changes in elevation, giving you a crisp throttle response and a smoother power band across the entire RPM range.

At Appletree Automotive, we know that no two VW engines are identical, and "off-the-shelf" carburetor settings rarely provide the peak efficiency your machine is capable of. These main jets are designed to fit the most popular Weber and EMPI carburetor platforms used in the air-cooled world, including the iconic 32/36 DGV progressive and the versatile 34 ICT series. The 120 orifice size is a common choice for those looking to fine-tune their mid-range performance, providing a gateway to better fuel economy and cooler cylinder head temperatures when paired with the correct air correction jets. Whether you are building a daily driver or a weekend trail-runner, having a selection of these jets in your toolbox is the hallmark of a true VW enthusiast who understands that the difference between a "good" engine and a "great" engine lies in the smallest details of the carburetor''s internal calibration.

FITMENT

This main jet is designed for use with the following carburetor models and typical Volkswagen applications:

• Compatible Carburetor Series: Weber DGV, DGAV, DGEV (Progressive), Weber DFV, DFAV, DFEV, Weber ICT (Single Barrel), and EMPI EPC 34 Series.
• Volkswagen Type 1: Beetle, Bug, and Super Beetle (1950-1979) equipped with aftermarket Weber or EMPI carb kits.
• Volkswagen Type 2: Bus, Transporter, Kombi, and Campmobile (1950-1971 with Type 1 upright engines or 1972-1979 with Type 4 pancake engines running dual ICTs).
• Volkswagen Type 3: Fastback, Squareback, and Notchback (1961-1973) running dual ICT or progressive conversions.
• Volkswagen Karman Ghia: All years (1955-1974) utilizing Weber or EMPI carburetor upgrades.
• Volkswagen Type 181: The Thing (1973-1974) with modified fuel delivery systems.
• Custom Applications: Dune Buggies, Sand Rails, and Trikes utilizing 1600cc to 2110cc air-cooled powerplants.

SPECS

• Jet Size: 120 (Equivalent to a 1.20mm precision-drilled orifice).
• Material: High-quality, corrosion-resistant machined brass for long-term fuel stability.
• Thread Type: Standard Weber/EMPI main jet threading for seamless installation.
• Compatibility: Fits the main fuel circuit (not for use as an idle or air correction jet).
• Stamping: Clearly marked with size "120" for easy identification in your jet kit.
• Sold Individually: Allows for precise ordering for single or dual carburetor setups.
• Manufacturing Standard: Precision CNC machined to meet or exceed original Weber specifications.

PRO TIPS

Pro Tip 1: The Spark Plug "Read" is Your Best Friend. After installing your new 120 main jets, it is critical to perform a "plug chop" to verify your air-fuel mixture. Run the engine at a sustained cruising speed (around 3,000 to 3,500 RPM) for a few minutes, then safely pull over and shut the engine off immediately without idling. Remove a spark plug and inspect the ceramic insulator. A light tan or "coffee with cream" color indicates a perfect mixture. If the plug is white or blistered, you are too lean and may need a larger jet; if it is sooty and black, you are too rich and should consider dropping a size. Don''t rely on idle quality to judge a main jet, as they operate on entirely different circuits.

Pro Tip 2: Avoid Over-Tightening Brass Components. These jets are made of high-quality brass, which is relatively soft compared to the carburetor body. When installing the jet into the jet carrier or the base of the bowl, use a flat-head screwdriver that fits the slot perfectly to avoid "burring" the brass. Tighten it until it is snug, but do not crank down on it. Over-tightening can distort the orifice or make the jet nearly impossible to remove later without damaging the carburetor housing. If you find yourself changing jets frequently while tuning, a dedicated jet tool is a wise investment to protect your hardware.

Pro Tip 3: Consider Your Altitude and Air Correction. Remember that a main jet does not work in a vacuum; it works in conjunction with your air correction jet. If you are driving at high altitudes (above 5,000 feet), the air is thinner, meaning you generally need a smaller main jet (like this 120) to prevent a rich condition. Conversely, at sea level, you might need to go larger. If you find that the 120 jet gives you great mid-range but the engine "stumbles" at the very top of the RPM range, you may need to adjust your air correction jet rather than changing the main jet again. Tuning is a balance of fuel and air; always change only one variable at a time so you can accurately track your performance gains.