This is the O.S. Max FS-70 Ultimate 4-Stroke Engine with Pump.

O.S. Max FL-70 4-Stroke Model Airplane Engine. This FL-70 engine provides easier handling and maintenance, lighter weight and lower cost to 4-stroke newcomers and Sunday fliers.

OS FS-40 surpass four-stroke model aircraft glow engine.

This is one of the O.S. Surpass series of 4-stroke model engines. The Surpass series is the 2nd series of 4-stroke engines (The 1st series was the FS series, discontinued and replaced by the Surpass series around 1986-7). "Surpass" refers to the fact that this series gained 30% more power than the previous FS series.

This is one of the O.S. Surpass series of 4-stroke model engines. The Surpass series is the 2nd series of 4-stroke engines (The 1st series was the FS series, discontinued and replaced by the Surpass series around 1986-7). "Surpass" refers to this series gaining 30% more power than the previous FS series.

FS-91 Surpass 4-stroke Engine with Pump Unit. This engine does not use a choke valve OR a return fuel line to the tank. There are No Tools OR Extra Needle Valve, as stated in the instructions.

This is the FS-91II Surpass 4-Stroke Engine. This engine does not use a choke valve OR use a return fuel line to the tank. THERE ARE NO TOOLS OR EXTRA NEEDLE VALVE AS STATED IN THE INSTRUCTIONS.

This is a FT-160 Twin-Cylinder 4-Stroke Engine from O.S. Max. This Engine is a Flat (Opposed) Twin-Cylinder Engine, called the Gemini-160". It is Scale-Like in Appearance when Installed in a Piper Cub or Citabria.

O.S. FT-300 Twin-Cylinder 4-stroke engine. This engine is a flat (Opposed) twin-cylinder engine, called the Gemini-300". It is scale-like in appearance when installed in a Piper Cub or Citabria.

O.S. Max IL-300 Dia-Star 4-Cylinder, 4-Stroke Inline Limited Edition Collector's Engine.

**The black colored Collector Exhaust Pipe shown in the photo**
*is optional and NOT included with this engine.**
**The engine will operate fine with the included exhaust pipe assemblies.**

Power your prized Giant scale plane with an O.S. Multi-Cylinder 4-Stroke Engine. The O.S. FF-320 (Nicknamed "Pegasus") is a Flat-Four Cylinder Engine. It is the ultimate in scale realism: abundant power, realistic noise levels, and scale appearance. This engine is covered by a 2-Year Warranty.

O.S. Max FR5-300 "Sirius" 4-Stroke, 5-Cylinder Radial Engine. This engine is very popular with the "Giant Scale" modelers with its abundant power, low vibration, smooth operation, and realistic noise levels. This engine is the masterpiece of O.S. Multi-Cylinder 4-Stroke Engines!

O.S. Max .46AX ABL BB model airplane engine with muffler. Ideally suited to a variety of R/C aircraft including trainer, sports aerobatic, and scale types.

O.S. Max .55 AX ABL aircraft engine with muffler.

OS Max 15CV-A R/C airplane engine with muffler. Add "CV" power to your racing or combat models with this airplane version of OS Max's popular buggy engine.

O.S. has updated the .25 SF with this New High-Performance .25 FX. This engine may be used in sport and aerobatic aircraft. The FX is designed to use a muffler or tuned pipe. Comes with a 2-Year Warranty.

OS .46LA engine designed for sport airplane use. This is a non-ringed engine with a Two-Year Warranty. This engine has a natural finish w/"O.S." & "46LA" on the side.

O.S. Ducted Fan engines are designed to develop high power at high RPM. These are used in jet (Ducted Fan) models where the engine drives a turbine-like impeller (compressor) that draws a large quantity of air through a shroud to create thrust. These engines are NOT covered under the O.S. 2-year warranty, (due to the high-performance nature of this engine, reliability is sacrificed). The Ducted Fan DOES NOT come with this engine. One must purchase the fan to fit BOTH the engine size and the specific plane (these fan units are typically manufactured by the same people who make the plane kit - like Jet Hangar Hobbies.

This is the .70 SZ-H Ring Engine from O.S. designed with the FAI F3C Pilot in mind.