Naraku 50cc QMB139 4-stroke 52.4mm, Racing Big Bore Cylinder and Head Kit. Kit includes cylinder, piston, rings, piston pin, cir clips, cylinder head, head gasket, and base gasket.
When used in conjunction with a stock stroke of 41.4mm the total displacement comes out to 89.3cc! When used with a 44mm stroker crank, total displacement measures 94.9cc!
Upgrades to 89.3ccCylinder Bore: 52.4mmCylinder Sleeve Outer Diameter: 54.4mm Wrist Pin Diameter: 13mmTotal Piston Height: 36.3mmCompression Height (from center of wrist pin hole to top edge of piston): 20mmNon-emissions style headIntake valve: 23mmExhaust valve: 20mmIntake Port Diameter: 20.8mmExhaust Port Diameter: 18.7mmUses Short 64mm Valve Stems
*You may need to modify your engine case to accommodate the larger cylinder.
Please note: replaces Cylinder Heads with 64mm Valves (Short Valve Style). Please see Related Items if you need 64mm valves. You may need to modify your engine case to accommodate the larger cylinder.