The Zenoah 62 is very popular engine for scale aircraft requiring a 60cc engine. The very wide and cleanly formed cooling fins allow the use of large propellers causing the motor to turn at relatively low speeds. For aerobatic aircraft the 22x10" or the 22x12" Menz S propeller has proved to be very good or aircraaft such as glider tugs typically flies best with the 24x10".
If you wish to, or must, reduce the engine noise, you can pull the intake air out of the fuselage by fitting a 90 degree bend between the carburettor and motor. The intake noise is louder than the noise from the standard silencer. This bend by lengthening the intake tract allows the fitting of a 24x12" or 26x10" Menz S propeller, of course you are not going to get the maximum power from the motor by this method.
The ZG 62 SL is delivered complete with silencer, fitted with 40 mm prop hub, but without motormount.Specifications:
Capacity: 62 cc
Bore: 47,5 mm
Stroke: 35 mm
Power: 4,3 hp
with tuned pipe: 6,6 hp
Weight: 2040 g without silencer and engine mount