Fiala FM 250 R5-4T Starter

Exceptionally lightweight — approximately 2 lb lighter than comparable four-stroke engines in its class

High propeller efficiency — capable of turning large-diameter propellers efficiently within a practical RPM range

Distinctive four-stroke sound — large Honda valves and carefully engineered valve timing produce a deep, pleasing exhaust note

Excellent throttle response — immediate response with smooth, predictable transition throughout the mid-range

Compact frontal profile — valve train, carburetor, and exhaust components are positioned behind the cylinder to minimize frontal area

Nickel-silicon-plated cylinder surfaces for excellent wear resistance and durability

Fully enclosed valve train for improved protection and long-term reliability

Single-camshaft design for mechanical simplicity and reduced component count

Three-bearing crankshaft support for increased rigidity and durability

Microprocessor-controlled ignition with automatic ignition advance and retard

2S LiPo-compatible ignition system for convenient, lightweight power

Modern engineering — FM engines are designed using current engineering tools, manufacturing methods, and design techniques

Fuel consumption is approximately 50% lower than that of a comparable two-stroke engine of the same displacement

This is the Deluxe 250-class radial engine, featuring a complete CNC-machined engine for exceptional precision, strength, and consistency.

APS Fuel Pump Included — a $245 Value

The engine comes complete with the APS-manufactured fuel pump, eliminating the need to purchase or engineer a separate pump system.

Install in Any Orientation

The engine can be installed in any rotational orientation, providing considerably more flexibility when fitting it inside narrow or scale cowls. Any cylinder can be positioned exactly at the 6 o’clock position, allowing you to optimize cylinder placement for your particular installation.

Features

Designed Specifically for Fuel-Pump Operation
This engine was engineered from the ground up for use with a fuel pump. The Fiala/APS fuel pump is included as standard equipment.

Fully Enclosed Valve Train
The enclosed valve train provides a clean, compact installation while protecting critical valvetrain components.

Laser-Welded Stainless-Steel Exhaust Ring
The stainless-steel exhaust collector ring is laser welded and particularly well suited for custom exhaust installations. This makes it considerably easier to fabricate scale exhaust systems and position exhaust outlets in the correct locations for highly detailed scale builds. Stainless steel construction also simplifies welding and brazing of custom exhaust components.

Smart Electronic Ignition — 4.5V to 9V
The intelligent ignition system provides acoustic status feedback and monitors engine RPM during startup. Its integrated startup protection prevents the engine from inadvertently being started at full throttle.

Versatile, Heavy-Duty Engine Mount
The large engine mount simplifies installation and provides multiple mounting options. The engine can be installed using standoffs or mounted directly to the firewall, depending on the aircraft and installation requirements.