O.S. Engines 25LA User Manual
Page 14
A
B
75%
20%
5%
65%
20%
15%
Methanol
Castor Oil
Nitromethane
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 flammable.
Keep it away from naked 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.
Reminder!
7
✕
4
8
✕
4
9
✕
5
10LA
15LA
25LA
7
✕
3
~
5,8
✕
4
7
✕
5
~
6,8
✕
4
~
5
9
✕
5
~
6
PROPELLER
Suggested propeller sizes are given in the table. As
the ideal propeller diameter, pitch and blade area vary
according to the size, weight and type of model, final
propeller selection can be made after practical
experiment.
Trainer & Sport
LA Series
Never touch, or allow any object to come
into contact with, the rotating propeller and
do not crouch over the engine when it is
running.
Running-in
Reminder!
GLOWPLUG
An O.S. A3 glowplug is fitted to the engine.
Other recommended O.S. plugs are Nos.8 and A5.
Carefully fit plug finger-tight, before final tightening
with the correct size plug wrench.
The role of the glowplug
With a glowplug engine, ignition is initiated by the
application of a 1.5-volt power source. When the battery
is disconnected, the heat retained within the combustion
chamber remains sufficient to keep the plug filament
glowing, thereby continuing to keep the engine running.
Ignition timing is 'automatic' : under reduced load,
allowing higher rpm, the plug becomes hotter and,
appropriately, fires the fuel/air charge earlier;
conversely, at reduced rpm, the plug become cooler and
ignition is retarded.
13