Yet it’s the well-muffled engine that sets the Kawasaki apart from its single-cylinder competition. Roll the throttle on from around 4,000 rpm and a thrum of torque shivers through the seat and tank as the revs climb to 5,000. It’s a mild, cute grunt, reminiscent of a kitten arching her back in an attempt to appear larger than her foe. After 5,000 rpm business picks up and acoustic waves echo from the airbox while the crankshaft shuttles both 62mm pistons through an ultra short 49mm of stroke at 7,000 rpm. This is the only place where the slightest bit of vibration sneaks out of the engine. It’s so minor I wouldn’t mention it at all but we’re supposed to nit-pick. From 7,000 on a long, insistent scream announces that you are in the fun zone and the sky’s the limit as long as the sky is ‘round about 12,800 rpm where the rev limiter causes the bike to stumble and fart.