Autolite AR3910X Racing Plug

Engineered specifically for lawn mowers, chainsaws, trimmers, and other outdoor machinery, these spark plugs deliver exceptional performance and reliability. Many parts look similar, so it’s crucial to ensure you’re choosing the right replacement for your original equipment or engine model. Not sure? Use our Parts Lookup Tool to view part diagrams and find the correct replacement. Copper-glass seal bonds insulator, terminal post center electrode together; assures full required voltage at spark gap; gas-tight seal (100% leak proof) Multi-rib insulator reduces danger of "flash-over One-piece terminal post adds strength Resistor reduces radio frequency interference (RFI) and electrode erosion Cold-formed steel shell precision rolled threads Spark plug designed for use with outdoor power equipment engines. WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov