O.S. Engines FS155-a Alpha Series 1.55 4-Stroke Pumped Engine

200-size power in a 120-size package!

How do you get 200-size power from a 120-size engine? O.S. calls it the FS155-a. Since the FS155-a is a pumped 4-stroke, you’ll enjoy 2.6 hp at all times, regardless of tank position, attitude or fuel level. Its novel re-circulation system bathes working parts in constant lubrication, for less friction and wear!

The biggest engine in the 'Alpha' series has been designed with both aerobatic and scale modellers in mind.

Because it's a pumped 4-stroke, you’ll enjoy plentiful power regardless of tank position, attitude or fuel level

Instead of oil venting through the crankcase, it’s re-circulated to lubricate working parts — reducing friction and wear as well as cowl cleanup.

Includes the 70R regulating carb for superior throttle response and precise fuel metering.

Specifications:

Weight 805g (28.4oz) W/O Silencer

Weight 95g (3.35oz) Silencer

Displacement 25.36cc (1.548cu.in)

Bore 33.6mm (1.323in)

Stroke 28.6mm (1.126in)

Power Output 2.6PS @ 10000RPM

Practical RPM 2000 - 10000RPM