2018 Kawasaki H2 SX SE First Ride Review

Achieving the desired fuel efficiency while maintaining the low- to mid-rpm performance characteristics of the H2 platform meant improving the engine’s thermal efficiency by increasing the compression ratio from 8.5:1 to 11.2:1; this was done with new cast aluminum pistons with a revised crown, new cylinder head and cylinder. Squish is now 1mm instead of 4mm, and the new pistons are said to improve combustion and help prevent engine knock. Intake and exhaust cam profiles were shortened to match the reduced airflow requirements of street riding. Exhaust header pipes are 2.2mm smaller in diameter with connector pipes between cylinders which contribute to low-mid range torque and higher fuel efficiency – and a new muffler with less volume is 6.6 pounds lighter than the original H2 unit.