Keep your GY6 or QMB139 engine running with precise valve clearance using this replacement Rocker Arm Valve Adjustment Screw and Lock Nut Set. A worn or stripped adjustment screw is a common cause of valve noise and poor idle � this direct-fit set of two restores proper valve lash adjustment quickly and affordably.
Fits most 50cc 4-stroke scooters and ATVs using the QMB139 engine platform, including:
Tip: Always check valve clearance with a feeler gauge after adjustment. Intake and exhaust specs vary by engine � consult your service manual.
California Prop 65 Warning: www.p65warnings.ca.gov
