4143 Stroker Crankshaft Yamaha YFM 350 Raptor 2004

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 0.30 mm - 0.55 mm. Heavy-duty +4.00 mm increased engine stroke makes 379 cc. Requires use of Stroker piston. Includes: • Crankshaft • MAG Crankshaft Bearing.