The 91HZ Ringed Heli Engine is a major player at heli competitions worldwide, and this newest version takes 3D performance to another level!

• The redesigned regulator is positioned horizontally, working with the PD-08 fuel pump it delivers a steady supply of fuel regardless of the helicopters attitude or demand on the engine.
• The piston and crankshaft are designed to reduce vibration and improve torque over the entire rpm range.
• The narrow profile of the heat sink head helps the 91HZ fit completely inside cooling shrouds without cutting or losing cooling power,and a thermo insulator on the 61B-PII carburetor blocks engine heat to ensure a stable fuel/air mix.
• Includes in-flight needle value adjustment arm.

SPECIFICATIONS
Stock Number: OSMG1977
Displacement: 0.91 cu in (14.95 cc)
Bore: 1.09 in (27.7 mm)
Stroke: 0.98 in (24.8 mm)
Practical rpm: 2,000-16,000
Power Output: 3.4 hp @ 15,000 rpm
Weight: 1.4 lb (635 g)
Includes: 61B-PII carburetor, #8 glow plug