The R61F rear exhaust engine has been updated. Better fuel economy and lower timing makes this engine operate a little more gentle on the airframes than the higher timed Speed 13 version. Includes venturi 20155.16mm with a 12+mm ID. 6mm spary bar assembly.
Not shown in photo.
Displacement: 9.98 cc
R.P.M. (max power)17.000 RPMPractical range: 2.000-20.400 R.P.M.
Bore x stroke: 23x24mm
Rear ball bearings: steel
Front ball bearings: steel
Crankshaft:18 mm̴ with 8 x 1.25mm Threads
Carburetor: aluminium - 9mm - Rotary
Glow plug: Standard Special (C6S)
Exhaust position: side