Improving on the Takegawa +R Superhead is tough. Takegawa has done it with the 4 valve SOHC Superhead bore kits. Increased efficiency through two 21.5mm intake valves, and two 18.5mm exhaust valves. Increased overall power with superlative gains in midrange horsepower and throttle response throughout the powerband. The only 4 valve cylinder head with Takegawa forged aluminum roller rockers for increased redline and no valve float.

The 106cc SCUT 4 valve Superhead bore kits come with the 4 valve Superhead, 10/15D decomp camshaft, 57mm skirtless piston and cylinder which requires no case boring or bottom end teardown on CRF50 base engines.