Designed for use with scooters, all-terrain vehicles, go-karts and other small machines, the Roketa carburetor is a single-barrel model that has just one idle adjustment screw. The rpm level depends on the size of the engine, and you can make the needed adjustments to the carburetor with a screwdriver and a vacuum gauge. The Roketa carburetor is manufactured in China, and is a simple device that you can regulate yourself without too much trouble.
Start the motor and let it run for about five minutes to warm up before attempting to adjust the carburetor. Detach the rubber vacuum hose at the base of the carburetor and attach a vacuum gauge to the port.
Turn the idle speed screw clockwise with a screwdriver until the motor starts to stall and turn it back counterclockwise 3/4-turn. If the engine stalls, start the motor again.
Turn the idle mixture adjustment screw counterclockwise until the vacuum gauge is reading about 1900 rpm for the 50-cc engine or about 1400 rpm for the 150-cc engine. Adjust the screw until you reach the maximum idle speed with the engine running smoothly.
Rev the engine a couple of times by moving the choke lever to verify that the adjustment holds steady when it returns to idle speed. Turn off the engine and remove the vacuum gauge. Reattach the rubber vacuum hose.