HPI Racing back plate unit is designed for the Nitro Star BB Series engine and the Force 21/25 (roto start). Designed for use with the Roto Start. Black nylon back plate. Steel constructed screws, hex tool, gears. Spare parts for HPI's Roto Start System, for Nitro Star BB, or Force 21/25. This product includes, (1) back plate unit, (1) 32T gear. (1) 11T Gear. (3) M2.6 x 12mm Caphead Screws. (2) M2.6 x 8mm Caphead Screws. (1) 2.0mm Hex Wrench.
Installation Onto Motor