O.S. Engines 21XZ-M - Manual (Page 6)

10
FUEL
Generally, it is suggested that the user selects a fuel
that is commercially available for model two-stroke
engines and contains 10-30% nitromethane. As a
starting point, we recommend a fuel containing 20%
nitromethane, changing to a fuel containing more
nitro if necessary. When the brand of fuel is changed,
or the nitro content increased, it is advisable to
repeat the running-in procedure referred to in the
RUNNING-IN paragraphs. Please note that with
high-nitro fuels, although power may
be increased for competition purposes,
glowplug elements do not last as long
and engine life will be shortened.
Items necessary for starting
REMINDER!
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.
TOOLS, ACCESSORIES, etc.
The following items are necessary for operating the engine. 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.
PROPELLER
Use well balanced propellers only. As the ideal
diameter, pitch and shape vary according to the
size, weight and type of model, final selection
can be made after practical experiment. As a
starting point, suggested propeller diameter is
41-43mm with a pitch/dia ratio of 1.0-1.1 for in-
drive Vee type hulls, 40-45mm with a pitch/dia.
ratio of 1.2-1.6 for out-drive Vee type
hulls and 44-46mm with a pitch/dia.
ratio of 1.4-1.6 for hydroplanes.
NOTE Never use a propeller that has even
slight damage.
11
TOOLS
GLOWPLUG IGNITER
Commercialy available handy glowplug
heater in which the glowplug battery
and battery leads are integrated.
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.
REMINDER! SILICONE TUBING
This is required for the connection between the
fuel tank and engine, also for the water cooling
system. Inner dia. of 2.3-2.5mm
and outer dia. of 5-5.5mm would be
suitable.
ELECTRIC STARTER AND STARTER BATTERY
Use a 12-volt electric starter
with suitable battery for start-
ing the engine.
Necessary for starting the engine.
It is suggested to keep a starter rope as a reserve.
STARTER BELT
Install a filter to the outlet tube of your
refuelling container to prevent entry of
foreign matter into the fuel tank.
SUPER FILTER (L) (Option)
O.S. SPEED DRIVER TOOLS
O.S. SPEED PLUG WRENCH