O.S. 12XZ ABC 12F Slide engine

The new O.S. 12XZ ABC 12F Slide engine features newly designed major parts that are designed to max out low- to mid-speed torque. Sporting a new crankshaft that features a counter-balancing shape and a more efficient intake port, the connecting rod is made of a new material, and the crankcase has been strengthened. Improvements have also been made to the liner ports, inner head and the 12F slide valve carb and it is supplied with a high-performance RP6 plug.

Specifications:
Displacement: 0.128 cu in (2.10 cc)
Bore: 0.543 in (13.8 mm)
Stroke: 0.551 in (14.0 mm)
Practical rpm range: 5,000-40,000
Power output: 1.65 ps @ 34,000 rpm
Engine weight: 8.32 oz (236 g)
Includes: RP6 plug, exhaust seal ring, dust caps

Source: OS Engines [osengines.com]