Royal Enfield Himalayan modified with NMW Racing big bore kit. Episode 2 of the Project HT500 shows the internals of the engine mainly the working of the 5-speed gearbox. br br Project HT 500 details: the Royal Enfield Himalayan receives a 500cc Big Bore Kit, Bigger Valves, Ported Engine Head, High-Lift Camshaft and a 4-Map Racing ECU. Stay tuned for more episodes on the project motorcycle.