Sport Rider Photos
A slightly more convex piston crown increases compression from 12.8:1 to 13.1:1. The titanium valves and camshaft profiles are all unchanged, but the exhaust timing has been advanced by one degree. New valve springs are made from an improved alloy but have the same rate as before, the connecting rod bearings are 1mm wider and made from a different material, and the main bearings are also a different material and have an increased oil supply. In all, more than 50 detail changes inside the engine were made to reduce friction. While the ramp-style slipper clutch is identical to the previous version, engine braking has been reduced by using the YCC-T to hold the throttle butterflies open slightly on deceleration.
2008 Yamaha YZF-R6 - Scream II