How to Adjust a Zama Carburetor

Set the engine on a hard, flat surface. Locate the carburetor on the side of the engine, directly under the air filter. On the side of the carburetor are three adjustment screws; there are stamped letters beside these screws, "L" for the low speed adjustment screw, "H" for high-speed adjustment and "TAS" for the idle adjustment.

Gently turn the "L" and "H" adjustment screws clockwise until they seat with the flathead screwdriver. Turn the "L" and "H" counterclockwise two full turns. Turn the "TAS" adjustment screw in clockwise until it seats.

Start the engine and allow to run for two to three minutes until the engine is at the operating temperature. Turn the "L" screw clockwise until the engine begins to slow, and then turn counterclockwise until the engine rpm's pick back up. Turn the "TAS" screw counterclockwise until the engine is at a steady reliable speed. Repeat the "L" screw adjustment above to ensure proper engine speed.

Advance the throttle to the FAST position, turn the "H" screw clockwise until the engine starts to slow, then turn counterclockwise until the engine speeds up and runs smoothly.