Marine thermal engine O.S. 20 FP-M 3.46 cm3

O.S. MAX 20 FP-M: a reference marine thermal engine for RC boats

Designed for enthusiasts of thermal radio-controlled boats, the O.S. MAX 20 FP-M embodies all the expertise of the Japanese manufacturer O.S. Engines, renowned for decades for the quality of its model engines.

Produced between the mid-1980s and the early 1990s, this marine engine belongs to the famous FP range, known for its robustness, ease of use, and longevity.

With a displacement of 3.46 cm³ (.21), the 20 FP-M develops approximately 0.5 horsepower at 16,000 rpm, while offering an extended operating range between 2,500 and 16,000 rpm.

Its water cooling system helps maintain an optimal operating temperature, even during prolonged use, ensuring consistent performance and excellent reliability.

A design built to last

Like the entire FP range, the 20 FP-M benefits from meticulous manufacturing.

Its Schnürle scavenging architecture, combined with quality materials and precision machining, provides a flexible, reliable, and easy-to-adjust engine.

This design still makes it a reference today for hobbyists looking for a simple-to-maintain and enjoyable-to-use marine thermal engine.

The starting is known to be easy, carburetor adjustments remain accessible even to inexperienced users, and the engine easily accepts the glow fuels commonly used in naval modeling.

An ideal engine for radio-controlled boats

The O.S. MAX 20 FP-M is intended for RC boats equipped with a transmission suitable for thermal engines. Its excellent balance between torque and speed enables it to effectively propel many leisure or speed boat models.

Its lightweight of approximately 210 grams also facilitates its integration into many hulls while maintaining a good overall balance.

Important information regarding accessories

Contrary to what some photographs may suggest, the O.S. MAX 20 FP-M engines were never originally supplied with the flywheel or exhaust manifold.

These two components were offered separately to allow modelers to adapt the engine to their installation and the transmission used. If your project requires these accessories, they will need to be purchased separately from the engine.

Why choose an O.S. Engines engine?

For over half a century, O.S. Engines has been one of the most renowned manufacturers in the field of thermal engines for model vehicles.

The FP series perfectly illustrates this expertise with robust, precise engines designed to offer a long service life.

Even today, the O.S. MAX 20 FP-M remains a particularly popular engine among collectors and modelers looking to restore or equip a radio-controlled thermal boat with an authentic, high-performing, and reliable engine. Thanks to its quality construction, ease of use, and the availability of numerous spare parts, it remains a safe bet in the world of naval modeling.