4105 Stroker Crankshaft Yamaha YFS200 1988 2006

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.. +4.00 mm stroke increase makes 209 cc displacement with standard piston. IMPORTANT: Head Chamber area must be machined 2.00 mm deeper and the engine cases will need to be bored out to accept the longer stroke crank..