Riding the 2004 Yamaha YZF-R1

Yamaha really appears to have pulled out all the stops in designing the R1's entirely new engine (Suzuki didn't leave it much choice). To achieve a rather amazing redline of 13,750 rpm (a full 2,000 rpm higher than last year's motor), Yamaha went with an extremely over-square engine architecture, increasing bore by 3 mm, and decreasing stroke by nearly 4 and 1/2 mm. Claimed peak horsepower is 180 (with ram air effect) and 172 (without ram air).