Brosol/Solex Main Jets 140

OVERVIEW

Precision tuning is the difference between a Volkswagen that simply runs and one that truly performs. The EMPI Brosol/Solex Main Jet in size 140 is an essential component for any air-cooled enthusiast looking to dial in their fuel-to-air ratio for peak efficiency and power. Located at the bottom of the float bowl, the main jet controls the volume of fuel delivered during the high-speed circuitessentially everything off-idle and through the top end of your RPM range. If you have recently upgraded your exhaust to a high-flow header, installed a larger displacement piston and cylinder kit, or are dealing with the leaner combustion characteristics of modern ethanol-blended pump gas, moving to a 140 main jet is often the silver bullet for eliminating "flat spots" and preventing the dangerous "lean-out" conditions that lead to overheated heads and burnt valves.

At Appletree Automotive, we understand that "close enough" isn''t good enough when it comes to carburetion. These jets are manufactured to exacting tolerances to ensure consistent flow rates across every unit we sell. The 140 size is a popular choice for 1600cc and 1641cc engines running the classic 34 PICT-3 carburetor, providing that extra bit of fuel needed to keep combustion temperatures in check while maximizing throttle response. Whether you are daily driving a Beetle through stop-and-go traffic or pushing a heavy Westfalia Bus up a mountain pass, having the correct main jet size ensures your engine remains in its happy place. These are genuine EMPI components designed to thread perfectly into original Solex castings as well as modern Brosol and replacement H30/31 units, making them a versatile staple for any VW toolbox.

FITMENT

This main jet is designed for use with Solex, Brosol, and EMPI branded carburetors commonly found on the following air-cooled Volkswagen models:

• Volkswagen Beetle: 1950 through 1977 (Standard and Super Beetle)
• Volkswagen Karmann Ghia: 1956 through 1974
• Volkswagen Bus / Transporter / Type 2: 1950 through 1971 (1600cc Dual Port engines)
• Volkswagen Type 3 (Squareback, Fastback, Notchback): 1961 through 1973
• Volkswagen Thing (Type 181): 1973 through 1974
• Carburetor Models: Solex 28 PICT, 30 PICT-1, 30 PICT-2, 30 PICT-3, 31 PICT-3, 34 PICT-3, and Brosol H30/31

SPECS

• Part Number: 43-5140-7
• Jet Size: 140 (1.40mm orifice)
• Material: High-quality machined brass for corrosion resistance
• Thread Type: Standard Solex/Brosol main jet pitch
• Compatible Fuel Types: Gasoline, E10, and E15 Ethanol blends
• Circuit Type: High-speed / Main fuel circuit
• Quantity: Sold individually (Each)

PRO TIPS

1. The "Plug Chop" Method for Verification

After installing your new 140 main jet, it is critical to verify that the mixture is correct. We recommend performing a "plug chop." Take your VW out for a drive and get it up to operating temperature. Find a safe, open stretch of road and hold a steady 55-60 MPH for about 30 seconds, then immediately turn off the ignition and coast to a stop (be careful as you will lose power steering if equipped, though most vintage VWs don''t have it). Pull a spark plug and inspect the ceramic insulator. If it is a light "toasty" tan color, your 140 jet is spot on. If it is white or blistered, you may need a 145; if it is sooty black, you might need to drop back down to a 135 or 137.5.

2. Compensating for Modern Ethanol Fuels

Modern pump gas often contains 10% to 15% ethanol, which burns leaner than the pure gasoline available when your Solex carburetor was originally engineered. Because of this, the factory jetting (often a 127.5 or 130 in a 34 PICT-3) is frequently too lean for today''s environment. Upgrading to a 140 main jet is one of the most common "stage one" tuning secrets to compensate for this chemical change in the fuel. This slight increase in fuel volume helps cool the cylinders and prevents the "stumble" many drivers experience when transitioning from the idle circuit to the main circuit under load.

3. Altitude and Jetting Dynamics

Always remember that air density dictates your jetting needs. If you live at a high altitude (above 5,000 feet), the air is thinner and contains less oxygen, meaning you typically need a smaller jet to maintain the correct ratio. However, if you are at sea level or in a cold, dense-air climate, a 140 jet is often the perfect "sweet spot" for a 1600cc engine with a stock or mild camshaft. Don''t forget to check your vacuum advance and timing as well; a carburetor is only as good as the ignition system supporting it. Always ensure your float level is set correctly before swapping jets, as an incorrect fuel bowl level will skew your jetting results.