O.S. Engines 120AX - Manual (Page 6)

10
FUEL
The 120AX RING should be operated on a methanol
based fuel containing not less than 18% (volumetric)
castor oil, or a top quality synthetic lubricant (or a
mixture of both), plus a small percentage (5-20%) of
nitromethane for improved flexibility and power. (The
carburetor is adjusted a little on the rich side at the
factory for a fuel containing 20% lubricant and 15%
nitromethane.) Some commercial fuels also contain
coloring additives as an aid to fuel level visibility. In
some cases, these additives have indicated slightly
negative effects on the 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.
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 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.
Reminder!
A fuel tank of approximately
350cc capacity is suggested.
This allows around 10-12
minutes flying time, dependent
upon the type of fuel used, the size of propeller
and on the amount of full-throttle to part-throttle
operation throughout the flight.
Fuel Tank
GLOW PLUG
O.S. No.8 glowplug is supplied with the
engine.
11
GLOWPLUG IGNITER
Commercialy available handy
glowplug heater in which the
glowplug battery and battery
leads are integrated.
Alternatively, one of the
purpose-made manual or
electric fuel pumps may be
used to transfer fuel directly
from your fuel container to
the fuel tank.
FUEL PUMP
Manual
Electric
Electric Starter and
Starter Battery
Required when starting
the engine.
12-Volt lead-acid battery
Electric Starter
Install a filter on the outlet tube of your
refueling container to prevent entry of
foreign matter into fuel tank. O.S.
Super Filters (large and small) are
available as optional extras.
O.S. Super Filter (Fuel Can Filter)
To prevent the pickup from adhering
to the tank wall under suction and
restricting fuel flow, slots may be filed
I the end of the weight. Alternatively,
O.S. Non-Bubble Weight is available
as an optional extra.
It is recommended to install a good
in-line filter between the fuel tank
and carburetor to prevent entry of
foreign matter into the carburetor.
O.S. Non-Bubble Weight
Fuel Filter
SILICONE FUEL LINE
Heatproof silicone tubing of
approx. 5mm o.d. and 2.5mm
i.d. is required for the
connection between the fuel
tank and engine.