O.S. engine 49-PI II Instruction Manual page 7

Electric Starter and
Starter Battery
Required when starting
the engine.
12-Volt lead-acid battery
Fuel Filter
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. Super Filter (Fuel Can Filter)
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.
Fuel Tank
A fuel tank of approximately
320cc 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.
Spinner
Since the 55AX is intended to be
started with an electric starter, the
addition of a spinner assembly for
centering the starter sleeve is desirable. Use a
heavy-duty, well balanced spinner either of
metal or plastic.
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.
O.S. Non-Bubble Weight S
Electric
Starter
The engine is supplied with a small
sized Non-Bubble Weight. Be sure
to use it in a fuel tank installed in a
model.
Since the distance from the carburetor to the
expansion chamber in the housing is very
short with a rotary engine, even a tiny bubble
from the fuel tank will cause engine breathing.
The Non-Bubble Weight will prevent from
sucking bubbles.
This Non-Bubble Weight can be used for
reciprocating engines. Especially it is suitable
for helicopter engines and big engines which
generate bubbles due to vibration. Also, it is
suitable for sub tank for helicopter as it has
small dia. of 10mm.
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Propellers
The choice of propeller depends on the design
and weight of the aircraft and the type of flying
in which you will be engaged.
Determine the best size and type after
practical experimentation. As a starting point,
refer to the props listed in the accompanying
table. Slightly larger, or even slightly smaller,
props than those shown in the table may be
used, but remember that speed the propeller
noise will increase if blade tip is raised, due to
higher rpm or if a larger-diameter/lower-pitched
prop is used.
9x6-7, 10x4-6, 11x4-5
The above propeller sizes are just for a guide.
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SIZE （DxP）