This is the Ninja JX21-B04 Off-Road Buggy Engine. The innovative JX21-B04 engine includes a new fuel efficient carburetor with 6.5mm reducer. The new carburetor provides smoother easy to drive power and increased fuel efficiency. The B04 comes with a tungsten weighted crankshaft with DLC coating. The lightweight cooling head provides exceptional cooling and stable operating temperatures.
|Displacement||：||0.211 cu in (3.46 cc)|
|Bore||：||0.646 in (16.40 mm)|
|Stroke||：||0.646 in (16.40 mm)|
|Rear Ball Bearings||：||Steel|
|Front Ball Bearings||：||Steel|