User Manual
12
FUEL
The 55AX 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.
13
S
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.










