Radio-controlled thermal engine Spark plug O.S. CM-6 / O.S. GT-55

Bougie O.S. CM-6

High reliability spark plug for O.S. GT-55 gasoline engine

I find this reference particularly important on a 55cc engine where thermal constraints become much higher than on small RC gasoline engines.

The CM-6 offers excellent resistance to high temperatures while ensuring stable and consistent combustion.

Thanks to its specific design for gasoline engines with electronic ignition, it ensures:

• reliable ignition,
• excellent engine stability,
• smooth acceleration,
• clean operation,
• very good mechanical endurance.

A spark plug suitable for high-displacement RC gasoline engines

The O.S. GT-55 engine develops significant torque and operates in a high rpm range for a model gasoline engine.

A standard spark plug would not sustain:

• combustion temperatures,
• vibrations,
• mechanical stresses,
• prolonged high rpm phases.

The O.S. CM-6 has been developed to meet the specific needs of high-displacement RC gasoline engines used in:

• aerobatic airplanes,
• giant warbirds,
• semi-scale airplanes,
• 3D airplanes,
• large RC airplanes.

I also notice that it significantly contributes to idle stability, a crucial point on large gasoline engines where vibrations can disrupt operation.

Stable combustion for consistent performance

With the CM-6 spark plug, the engine maintains uniform combustion even under heavy loads.

This allows for:

• cleaner accelerations,
• better stability at full throttle,
• fewer engine misfires,
• better controlled engine temperature.

On a gasoline RC airplane, this consistency becomes particularly important during:

• extended vertical climbs,
• full throttle passes,
• aerobatic maneuvers,
• low throttle approaches.

I find that this spark plug clearly helps make the engine more enjoyable and safer to operate.

Differences with a classic nitro glow plug

Unlike glow plugs used in methanol engines:

• the CM-6 operates with an electronic ignition system,
• it is designed for gasoline,
• its thermal resistance is much higher,
• its electrode is adapted to the high compression of RC gasoline engines.

A classic nitro plug would not function properly on the GT-55 and would not withstand the engine's stresses.

Why choose an original O.S. spark plug?

I always recommend using a spark plug that is suitable and approved by the manufacturer on this type of high-end engine.

With the O.S. CM-6 spark plug, you benefit from:

• perfect compatibility,
• optimized operation,
• excellent reliability,
• easy starting,
• consistent combustion.

The manufacturing quality of O.S. Engines remains a true reference in the world of thermal aeromodeling.

Compatibility

This spark plug is specially designed for:

• O.S. GT-55 engine,
• RC gasoline engines with electronic ignition,
• large RC airplanes,
• aerobatic and warbird airplanes.

Recommended Applications

• 50cc to 60cc RC gasoline airplane
• 3D aerobatics
• Giant warbird
• Semi-scale airplane
• RC gasoline competition airplane

Key Features

• Special spark plug for RC gasoline engine
• Compatible with O.S. GT-55
• Excellent thermal resistance
• Very good engine stability
• Consistent operation at high speeds
• Reliable starts
• High manufacturing quality from O.S. Engines