New from HPI is the Roto Start system for the HPI K Series engines, including the extremely powerful K4.6! The HPI Roto Start system replaces the standard pullstarter with a durable metal gear backplate and a handheld shaft driven starter, making starting engine as simple as pressing a button. Available in two versions, one with the complete Roto Start handheld starter plus the engine backplate, and another with just the engine backplate.Requires a 7.2v rechargeable "stick" battery pack and charger. #2029 HPI Ni-Cd Battery Pack and #9058 Overnight Charger for 7.2v Ni-Cd Battery (AC120v) recommended. Some disassembly of the kit and engine is required. Complete instructions are included.