The 150cc carburetor is typically used on small engines that operate equipment like scooters, dirt bikes and go-carts. Adjusting the carburetor is a job that can be done in just a few minutes and will keep your engine running efficiently. The 150cc carburetor is adjusted with a single screw on the side of the carburetor barrel. Save yourself some time and money by adjusting the carburetor on your own.
Locate the idle adjustment screw on the side of the 150cc carburetor. The idle adjustment screw on this engine is normally a gold colored screw on the side of the carburetor.
Turn the engine on and let it warm up for about five minutes. Remove the rubber vacuum hose from the metal port on the side of the carburetor and attach a vacuum gauge to the port.
Turn the idle adjustment screw clockwise gently with a screwdriver until the screw is at the bottom and turn it clockwise 3/4 of a turn to prevent the engine from stalling. Do not over tighten the screw or you can damage the idle adjustment.
Adjust the idle mixture screw by turning it counterclockwise 1/2 turn at a time until you reach 1400 rpm's on the vacuum gauge. Accelerate the engine a couple times to verify that the engine continues running at the idle speed.
Remove the vacuum gauge from the port on the carburetor and reattach the rubber vacuum hose to the port of the 150cc carburetor.
