📘 AI Summary: Carburetor tuning baseline calculator. Adjusts air-fuel ratio for altitude (sea level to 10,000ft), air temperature, and engine size. Outputs recommended main jet change or mixture screw turns.

Carburetor Tuning Calculator

Tool description: Get a starting point for jetting or mixture adjustment when driving at different altitudes or temperatures. Works for most vintage carbs (Weber DGV, SU HS, Stromberg, Holley).

Engine Displacement (cc):

Altitude (feet above sea level):

Air Temperature (°F):

Carburetor Type:

Understanding Air-Fuel Mixture Adjustments

As altitude increases, air density decreases, requiring a leaner mixture (smaller jets or turning mixture screw inward). Higher temperatures also reduce density. Our calculator applies standard correction factors used by racers and classic car mechanics.

Fine-Tuning Tips

Always start rich and lean out gradually
Read spark plug color after a run
Altitude changes >2000ft need jet changes on most carbs

Last updated: May 10, 2026