O.S. Engine 91HZ  [OSMG1975]

With back-to-back FAI globe championships in 2005 and 2007, the 91SZ-H was successful by anyone's criteria. Now there's the 91HZ ?V a 91SZ-H redesigned aided by the information worldwide's top pilots. It includes the tuning ease and gratification persistence of the multi-time world champ and design innovations that promote enhanced cooling, a tighter compression seal ?V and tuning simplicity!

The slim profile of this temperature sink head helps the 91HZ fit totally inside cooling shrouds without cutting or losing cooling power!
Two heat sinks ?V one on mind, another regarding the crankcase ?V enable airflow to hold away heat and continue maintaining performance.
Better overall stability reduces motor sound and promotes smoother, stronger performance.
The latest 61B carbohydrate takes consistency to the next level. Dependability features focus on an insulating ring which prevents crankcase temperature from impacting carb settings. a generous use of O-ring seals ?V two regarding the main needle, one in the rotor ?V stops atmosphere leaks and power fluctuations.
In-flight control of this needle valve guarantees smooth, constant runs.

Specifications:

• Stock Number: OSMG1975
• Displacement: 0.912 cu in (14.95 cc)
• Bore: 1.091 in (27.7 mm)
• Stroke: 0.976 in (24.8 mm)
• Body weight: 21.8 oz (618 g)
• Practical RPM Range: 2,000-16,000
• Production: 3.4 hp @ 15,000 rpm
• Includes: 61B carburetor, muffler, in-flight needle valve adjustment arm & #8 radiance plug