Hoca 52mm QMB139 Performance Cylinder Kit, Part #169-342
Hoca 50cc QMB139 4-stroke 52mm, Racing Big Bore Cylinder Set. Kit includes cylinder, piston, rings, piston pin, cir clips, head gasket, and base gasket. When you use this Hoca 52mm Big Bore Cylinder Set in conjunction with our 44mm Stroker Crankshaft you will increase your total displacement to 93.4cc, almost doubling your original displacement!!! We recommend that you use our QMB139 performance cylinder head with this set as so.me stock cylinder heads will not fit. Use with an un-modified stock head can cause serious engine damage. You may need to modify your engine case to accommodate the larger cylinder. We recommend that you use our QMB139 performance cylinder head with this set as so.me stock cylinder heads will not fit. Upgrades to 87.9cc. Cylinder Bore: 52mm. Cylinder Sleeve Outer Diameter: 54.8mm. Wrist Pin Diameter: 13mm. Total Piston Height: 34.8mm. Compression Height (from center of wrist pin hole to top edge of piston): 17.25mm.