


The carburetor is adjusted for normal operation during produc- tion. I: The I (IDLE) screw controls the throttle opening toĬAUTION: increased idle speed may cause chain movement.Optimal adjustment is found between 1 and 1 1/4 turns. If the engine speed is too high, open the screw about 1/8 turn (counterclockwise). Then open screw 1 full turn (counterclockwise). To set hi speed screw H: close screw H turning it clockwi- se without forcing. H: The needle screw H governs fuel flow at high speed.If acceleration is not smooth, open another 1/8 turn to increase fuel flow. To set screw L: close screw L turning it clockwise without forcing. L: The needle screw L governs the fuel flow at low speedĪnd also the acceleration from low to full speed.The carburetor has three adjustment screws: Basic housekeeping includes regular back-ups plus some other, less familiar, tasks.We suggest carburetor adjustments are made by an authori- zed servicing dealer. Maintaining your MacBook keeps it running fast and smooth.

