Complete replacement motor for 150cc GY6 4-stroke engines 157QMJ with long engine block and rear drum brake. For the long engine block a 842mm belt is needed. Length of the motor can be determined by the distance of the crankshaft (variator) to the transmission input shaft (clutch housing). This distance is approximately 28cm in this replacement engine. The engine is supplied complete with transmission, alternator, etc., and is ready for installation. Deviations may occur in the transmission output shaft. There are two variants: Motor with short or long output shaft (the shaft on which the rear wheel is mounted). The short output shaft is used in vehicles with a rear shock, the long shaft for vehicles with two rear shock absorbers. In this engine here, a long transmission output shaft is installed. If the short shaft are required, they can easily be taken from the original engine. Important! Check the oil level in the gearbox and the engine after installation. Due to the oil quality used by Chinese manufacturers, we recommend changing the oil after 50km running-in period. The valve clearance should also be checked. Both valves a measure should be set by 0.08mm. Overall, this complete engine represents an economical alternative to expensive repair bills.