O.S. 18510 - OS 91RZ-H DH Ring Engine w/60M-C Carb.

This is the O.S. Max .91 RZ-H DH Rear Exhaust Helicopter Engine. Brand New in Box

Features:
Diecast cylinder head
Designed for Hirobo and other scale helicopters where engine must fit inside canopy to preserve heli's scale lines
Ringed piston
60M-C 3-needle carburetor with mid-range needle for precise adjustments
Includes:

O.S. Max .91 RZ-H DH Rear Exhaust Helicopter Engine with #8 glow plug, instruction manual

Specs:
Displacement: 0.912 cu in (14.95 cc)
Bore: 1.091" (27.7mm)
Stroke: 0.976" (24.8mm)
Practical RPM: 2000-16,000
Power Output: 3.3 ps @ 15,000 RPM
Weight: 22.0oz (623g)
Crankshaft Size: 5/16-24
Distance Between Mounting Holes Same Side: 0.98" (25mm)
Distance Between Mounting Holes Opposite Side: 2" (52mm)
Distance From Back Plate to Front Bearing: 3.3" (83.8mm)
Distance From Back Plate to Crankcase Center: 1.1" (27.4mm)
Distance From Crankcase Center to Front Bearing: 2.2" (56.4mm)
Distance From Crankcase Center to End of Crankshaft: 3.5" (88.7mm)
Width at Mounting Tabs: 2.4" (61mm)
Width of Crankcase Below Mounting Tabs: 1.7" (42.6mm)
Distance from Throttle Lever to Center of Crankcase: 1.7" (42.5mm)
Distance/Bottom of Mounting Tab/Top of Cylinder Head: 3.2" (81.2mm)