This flywheel is made from same quality materials and with the same attention to detail and reliability that has come to be expected from ARC. For optimum performance we recommend running with a balanced rotating assembly. Flywheel comes with coil spacers. IMPORTANT If you want to use cooling fins with this flywheel, you will need to buy part number 711175. The fins that come on the Harbor Freight engine will not fit properly. Minimum .030″ air gap. Flywheel is set at 32 degrees BTDC with a stock key. Torque to 54 ft/lbs. Weighs 1.75 LBS Stock Diameter, Lightest Flywheel Available!