O.S. Engines 25LA - Manual (Page 11)

BEFORE STARTING
Tools, accessories, etc.
The following items are necessary for operating the
engine.
1 Fuel
Model glowplug engine fuel of good quality, preferably
containing a small percentage of nitromethane. (See
"Advice on selection of fuel, glowplug and propeller")
2 Glowplug
O.S. A3 glowplug is installed in the engine.
3 Propeller
Suggested size is 7x4(10LA), 8 X4 (15LA), or 9 X5
(25LA).
4 Glowplug battery
The power source for heating the glowplug may be
either a large heavy-duty 1.5volt dry cell, or preferably,
a 2-volt rechargeable lead-acid cell (accumulator).
1.5 volt heavy-duty
dry battery or 2 volt rechargeable
lead-acid cell (at least 5Ah)
If a 2-volt cell is employed,
use a resistance wire, as
shown, to reduce applied
voltage, otherwise element
will overheat and burn out.
Resistance coil
(nichrome wire)
Adjust applied voltage by changing the position of clip on
resistance coil until glowplug element is glowing bright red.
Battery leads
Raise
voltage to
increase
brightness.
Lower voltage to
reduce brightness.
Warning (Very hot)
Never touch the nichrome wire while the battery is
connected.
5 Plug wrench
Used for tightening glowplug. The
O.S. long plug wrench is available
as an optional accessory.
For tightening
glowplug
10