4149 Stroker Crankshaft Yamaha YZF250 2003 2013

Features: Factory assembled and trued to OEM specifications. Drop in replacement crankshaft requires no modification unless noted . CNC machined and dynamically balanced to suit the increased stroke. Add +2.00 mm to +4.00 mm of stroke depending on application. Uses stock piston unless noted. Main bearings not included . Can be matched with Cylinder Works Big Bore cylinders to get significant displacement and horsepower gains. Not re-buildable as the rods are shorter than OEM.. Connecting rod side clearance is 0.25 mm - 0.45 mm. +3.00 mm stroke increase makes 264 cc. Uses stock piston. Bolt in and go. When using Cylinder Works big bore cylinder kit it will make 285 cc..