O.S. Engine max-140rx Owner's Instruction Manual - page 3
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NOTES
This engine was designed for model aircraft. Do not attempt to use it for any other purpose.
Mount the engine in your model securely, following the manufacturers' recommendations, using appropriate screws and
locknuts.
Be sure to use the silencer (muffler) supplied with the engine. Frequent exposure to an open exhaust may eventually impair
your hearing.
Such noise is also likely to cause annoyance to others over a wide area.
Fit a top-quality propeller of the diameter and pitch specified for the engine and aircraft. Locate the propeller on the shaft
so that the curved face of the blades faces forward-i.e. in the direction of flight. Firmly tighten the propeller nut, using the
correct size wrench.
Always check the tightness of the propeller nut and retighten it, if necessary, before restarting the engine, particularly in
the case of four-stroke-cycle engines. A safety locknut assembly is provided. Always use it. This will prevent the propeller
from flying off in the event of a "backfire", even if it loosens.
If you install a spinner, make sure that it is a precision made product and that the slots for the propeller blades do not cut
into the blade roots and weaken them.
Discard any propeller which has become split, cracked, nicked or otherwise rendered unsafe. Never attempt to repair such
a propeller: destroy it. Do not modify a propeller in any way, unless you are highly experienced in tuning propellers for
specialized competition work such as pylon-racing.
Use an electric starter for this engine. The wearing of safety glasses is also strongly recommended.
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NOTES
Take care that the glow plug clip or battery leads do not come into contact with the propeller.
Also check the linkage to the throttle arm. A disconnected linkage could also foul the propeller.
After starting the engine, carry out any needle-valve readjustments from a safe position behind the rotating propeller.
Stop the engine before attempting to make other adjustments to the carburettor.
Adjust the throttle linkage so that the engine stops when the throttle stick and trim lever on the transmitter are fully
retarded. Alternatively, the engine may be stopped by cutting off the fuel supply. Never try to stop the engine physically.
Take care that loose clothing (ties, shirt sleeves, scarves, etc.) do not come into contact with the propeller.
Do not carry loose objects (such as pencils, screwdrivers, etc.) in a shirt pocket from where they could fall through the
propeller arc.
Do not start your engine in an area containing loose gravel or sand. The propeller may throw such material in your face
and eyes and cause injury.
For their safety, keep all onlookers (especially small children) well back (at least 20 feet or 6 meters) when preparing your
model for flight. If you have to carry the model to the take-off point with the engine running, be especially cautious.
Keep the propeller pointed away from you and walk well clear of spectators.
Warning! Immediately after a glowplug-ignition engine has been run and is still warm, conditions sometimes exist
whereby it is just possible for the engine to abruptly restart if the propeller is casually flipped over compression
WITHOUT the glowplug battery being reconnected.
Remember this if you wish to avoid the risk of a painfully rapped knuckle!
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The entirely new 23cc MAX-140RX has been designed
expressly for FAI aerobatic competition under the latest
F3A regulations which permit two-stroke engines to have
a much larger displacement than the 10cc limit imposed
hitherto. The 140RX continues the long established O.S.
MAX contest engine tradition of unsurpassed quality of
construction, durability, reliability, compactness, high
specific output and high power-to-weight ratio. The 140RX
takes into account the need to achieve greater durability
through improved resistance to the crankshaft and main
ball-bearing corrosion that may occur under the severe
operating conditions of highly competitive FAI turnaround
aerobatic flying. The 140RX is equipped with a new O.S.
Type 70A carburetor and O.S. Type PD-06 diaphragm fuel
pump, specially developed for this engine. This fuel
system provides stable power and consistent throttle
response at all times, irrespective of fuel tank location or
aircraft attitude. The 140RX is an engine for experts and, in
order to achieve the levels of performance of which it is
capable, it is vitally important to correctly match the
propeller and tuned exhaust system to the engine's
operating characteristics. If propeller size and/or silencer
length are incorrect, the engine may actually produce
lower performance than that of a conventional standard
engine. Therefore, please read through all the following
instructions carefully.
INTRODUCTION
Needle-valve sensitivity
If the needle-valve adjustment is found to be too critical
when using the standard needle fitted to the engine, this
may be replaced with the optional, less sharply tapered
needle (Code No.22681980), to de-sensitize adjustment.
BASIC ENGINE PARTS
Cylinder Head
Drive Hub
Pump Unit PD-06
Lock Nut Set
Carburetor Type 70A
Cover Plate
Crankcase
Crankshaft
INSTALLING THE GLOW PLUG
Carefully insert plug, with washer,
fingertight only, before final
tightening with the correct size
plug wrench.
Glow plug
Washer