This is the O.S. 55HZ Hyper Ringed Helicopter Engine with the 40L Carburetor. The O. S. 55HZ-H Hyper Ringed Heli engine is cause to rejoice for 3D heli flyers! The 55-HZ-H Hyper Ringed engine cranks out optimum power with a minimum of space!

• Ideal for 3D flight-power equal to .60 size heli engines
• Same mounting bolt pattern and silencer size as the OS 50SX-H Hyper
• Dual needle 40L carburetor with four arm throttle lever for use with a variety of servo brands
• Two year limited warranty through manufacturer beginning at the date of purchase

SPECIFICATIONS:

• Displacement: 0.55 cu in (8.93 cc)
• Bore: 0.91 in (23 mm)
• Stroke: 0.85 in (23.5 mm)
• Practical rpm: 2,000-17,000
• Weight: 14.39 oz (408 g)