cylinder head Naraku racing for Yamaha Cygnus, BWs 5ML 4V

4-valve racing cylinder head for use on big bore cylinders for Yamaha 5ML engines. The cylinder head features stiffer valves and springs. The inlet valves have a diameter of 22.3mm and the exhaust valves 20.3mm. Inlet connection: 25mm, exhaust has a cross section of 24mm. Not for 125cc original cylinders.