Naraku Crankshaft Heavy Duty 16 Tooth for QMB139 (137-78)

Naraku Performance Heavy Duty Crankshaft for 50cc, 4-Stroke QMB139 engines - Oil Pump Sprocket 16 Tooth.

OEM-Quality Naraku Crankshaft matches Japanese and Taiwanese alternatives. Kitted with high quality, heavy duty bearings which allow for longer service life and durability, this crankshaft is far superior to low cost Chinese crankshafts.

Matches the design and size of your original crank, making it a perfect choice as a standard replacement. Also, goes great with your Big Bore Kit. Pre-assembled with pressed bearings. Make sure you check that you have a 16 tooth oil pump drive gear!


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• NK100.81
• Heavy Duty
• 16 Tooth Oil Pump Drive Gear
• Includes Bearings
• Made in Taiwan