Naraku 52.4mm Performance Cylinder & Head Kit

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! Please see our Warranty & Returns Policy. 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.
Upgrades to 89.3cc
Cylinder Bore: 52.4mm
Cylinder Sleeve Outer Diameter: 54.4mm Wrist Pin Diameter: 13mm
Total Piston Height: 36.3mm
Compression Height (from center of wrist pin hole to top edge of piston): 20mm
Non-emissions style head
Intake valve: 23mm
Exhaust valve: 20mm
Intake Port Diameter: 20.8mm
Exhaust Port Diameter: 18.7mm
Uses Short 64mm Valve Stems
SUPPORTED MODELS: QMB139 50cc/49cc , Various unlisted makes/models