FUEL
PROPELLERS
Suggested propeller sizes are listed on page 14. The
suitability of the prop depends on the size and weight
of the model and type of flying. Determine the best
size and type after the engine has been run in. Check
the balance of the propeller before fitting it to the
engine. Unbalanced propellers cause vibration and
loss of power. Wooden propellers are to be preferred.
Some nylon propellers are not strong enough to
withstand the high power output of these engines
and a thrown blade can be very dangerous.
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.
Model engine fuel is also highly flam-
mable. Keep it away from open flame,
excessive heat, sources of sparks, or
anything else which might ignite it.
Do not smoke, or allow anyone else to
smoke, near to it.
Select, by practical tests, the most suitable fuel from
among the best quality fuels available in your country
for model use. For the best performance, a fuel
containing 5% to 20% nitromethane is preferable.
Lubricants may be either castor-oil or a suitable
synthetic oil ( or a blend of both ) provided that they
are always of top quality.
For consistent performance and long engine life, it is
essential to use fuel containing AT LEAST 18%
lubricant by volume. Some fuels containing coloring
additives tend to deteriorate and may adversely affect
running qualities.
Once a satisfactory fuel has been selected and used
for a while, it may be unwise to needlessly change
the brand or type. In any engine, a change of fuel
may cause carbon deposits in the combustion
chamber or on the piston head to become detached
and lodged elsewhere, with the risk of this causing
unreliable operation for a while. If, however, the
adoption of a different fuel is unavoidable, check the
engine for the first few flights on the new fuel, by
temporarily reverting to the running-in procedure.
Reminder!
Reminder!
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