Stage 5 racing cylinder kit 89cc suit Chinese / QMB

OK for racing! STAGE 5 for Chinese 4 stroke 50 - compatible with earlier stages Massive power boost! This Naraku Racing cylinder is the only cylinder available with a 52.4mm bore, and with its actual 89cc, it has the largest capacity among cylinders for the QMB139 (also called GY6 50cc) engines. The 89cc big bore makes for excellent torque and an impressive increase in engine power. Other manufacturers tend to overstate the effective swept volume, but this is the real thing. Included in the kit: an optimized head with maximum intake and exhaust sizes modified piston with coated rings gaskets The kit comes with everything you need to replace all necessary parts without any further conversions (although due to variance in Chinese scooter factories we can not guarantee direct fitment in every case). You can use the standard carburettor, but rejetting is usually required.   Does not fit SYM Orbit 50 without modification as the hole in the crankcase is too small to accept the bigger skirt of this kit.