SMJ Kabuto R21 Model'18 Engine
Based on the OS R2103, produced by Masayuko Miura and with collaboration with YURUGIX.
The R21 has a reviewed cylinder liner, crank shaft and main bearing uses a steel bearing. At slow to middle range, torque performance has improved. DLC coating, embedded tungsten-weight on the crank shaft and bottled-tuning performed. There is no change to fuel efficiency from the previous model. All are designed for perfect performance at high grip surfaces.