O.S. Engines FS-52S - Manual (Page 11)

Model engine fuel is poisonous. Do not
allow it to come into contact with the eyes or
mouth. Always store it in a clearly marked
container and out of the reach of children.
Reminder!
FUEL
The FS-52S is should be operated on a methanol
based fuel containing not less than 18% castor-oil, or
a top quality synthetic lubricant (or a mixture of both),
plus a small percentage (5-15%) of nitromethane for
improved flexibility and power. The carburettor is
adjusted at the factory for a fuel containing 20%
lubricant and 10% nitromethane. Some commercial
fuels also contain color additives as an aid to fuel
level visibility. In some cases, these additives have
indicated slightly negative effects on performance.
We would suggest that you use such fuels only if you
are satisfied that they do not adversely affect running
qualities when compared with familiar standard fuels.
When changing to a fuel brand or formula that is
different from the one to which you are accustomed, it
is a wise precaution to temporarily revert to in-flight
running-in procedures, until you are sure that the
engine is running entirely satisfactorily. The choice of propeller depends on the design and
weight of the aircraft and on the type of flying in which
you will be engaged. Determine the best size and type
after practical experimentation. As a starting point,
refer to the props listed in the accompanying table.
Slightly larger, or even slightly smaller, props than
those shown in the table may be used, but remember
that propeller noise will increase if the blade tip
velocity is increased or a larger-diameter / smaller-
pitch prop used.
PROPELLERS
Type Size (DxP)
Stunt planes 10x9-10, 10.5x8-9, 11x7-8
11x7-8, 12x6, 12.5x6 Scale models
Make sure that the propeller is well balanced. An
unbalanced propeller and / or spinner can cause
serious vibration which may weaken parts of the
airframe or affect the safety of the radio-control
system.
Warning:
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