Instructions

Data Elements: ucInstruction.aspx

Air Density Wheel Guide Jetting Tool

  1. Run engine at wide open throttle to find the best main jet. Start with large jets and work you way down while checking plugs, pistons, E.G.T.'s, etc., to get the best mixture for acceleration and top end. When this is achieved, check your RAD (Relative Air Density) gauge reading and jet size. You may have to stagger your jet sizes. This is the base line setting for this engine.

  2. Align the RAD gauge reading over the jet size on the RAD guide. This is the base line.

  3. To check jetting next time, set RAD guide on base line. Check RAD gauge reading and find the jet size under this number on RAD guide. Use the larger jet when between two sizes. Remember to check the RAD gauge often as temperature and barometric pressure sometimes change rapidly.

  4. Some things that affect jetting DO NOT change the RAD gauge reading, so jet with caution. Humidity and oxygen content in the air are two of them. Although they have little effect, you may have to change jet size slightly to correct for them.

    Low Humidity

    High Humidity

    Country Air

    City Air 

    -

    -

    -

    -

    Richer Jetting

    Leaner Jetting

    Richer Jetting

    Leaner Jetting

This is only a guide, so start with larger jet(s) and keep notes on air conditions and final jet sizes. Your RAD gauge may fit into the hold of the RAD guide in order to keep them together.

Related Products