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 note: replaces Cylinder Heads with 64mm Valves (Short Valve Style). 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
QMB139 50cc/49cc , Various unlisted makes/models
