O.S. engine GT33 - Flight & Maintenance

OS asm
Hi Checking prior to flight
€ When the engine is started, make sure the radio control
system works normally (distance test).
@ Engine does not run erratic with full throttle.
@ Idling is stable.
@ Responds positively to the throttle operation.
@ Warm-up is finished.
Warm-up is required as with full size aircraft and car engines.
Take off the model after warming the engine for approx. 10
seconds with full throttle.
E Precautions in flight
€ A slight engine rpm increase and decrease delay is
normal. Abrupt throttle operation will the cause engine to
quit. Move throttle smoothly.
€ Due to the construction of the carburetor, 70-8026 of
maximum power develops with half throttle.
If you feel uneasy with this, adjust with transmitter
function (exponential and throttle curve, etc.) or
differential of throttle linkage.
@ Cooling is more vitally important to a gasoline engine
than to a glow engine. If overheating symptoms (loss of
power at full throttle or exhaust note at mid speed
changes from cloudy one to clear one) are observed
during flight, immediately stop flying and carry out the
following countermeasures.
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OS. creme
FLIGHT & MAINTENANCE
1) Enlarge the air intake cutout on the cowling.
2) Enlarge the air outlet cutout on the cowling. (It is
vitally important.)
3) Partly cover the air intake cutout on the cowling where
air does not hit direct the engine.
4) Install an air guiding plate on the fuselage and cowling
so that cooling air may be guided to the cylinder
portion of the engine and muffler.
@ When the interval between the flights is short and the
engine is still hot, it may be possible overheating
symptoms are observed by circulating the head from the
former flight through the engine even if the overheating
symptoms were not observed during the former flight. In
this case, leave it until the engine is fully cooled down (in
hot weather, it may take more than one hour.) or run the
engine for 4 to 5 minutes at idling.
Hi Maintenance after the day's flights
Please pay attention to the matter described below to
ensure that your engine serves you well in regard to
performance, reliability and long life.
€ Check the tightening of each screw, especially engine
installing screws and silencer installing screws each
time. Also, for the first several flights, tighten the screws
after each flight.
@ As previously mentioned, it is vitally important to avoid
operating the engine in conditions where dust,
distributed by the propeller, may be deposited on the
engine and enter its working parts.
Remember to keep your fuel container closed to prevent
foreign matter from contaminating the fuel.
Install a fuel filter to prevent foreign matter in the fuel
container from entering the fuel tank. O.S. Super Filter
(L) is available as an optional extra.
Install an in-line fuel filter between the tank and
carburetor to prevent foreign matter in the tank from
entering the carburetor.
Clean these filters periodically.
If these precautions are neglected, restrictions of fuel
flow may cause the engine to cut out, or the fuel/air
mixture to become too lean causing the engine to
overheat.
With a gasoline engine rust hardly occurs. Check the
exterior to make sure there is nothing wrong and wipe
off any oil res.
Fill the carburetor with fuel at the conclusion of a day's
flying. (Pay careful attention to fire and ignition source
when carrying and storing the model.)
If the engine is stored without filling the carburetor, with
fuel the inside parts will dry out and not work properly at
the next running. If the engine quits out of fuel, refill the
carburetor with fuel.
When the engine is not to be used for a long period
(more than a year), remove the engine from the model,
clean the outside then remove the carburetor, and plug
all tubing. Clean inside the engine by rotating the
crankshaft with the engine immersed in container filled
with gasoline.
Also use gasoline to clean the outside of the carburetor.
Clean the outside only because the inside parts are
sensitive to foreign substances.
After cleaning the engine, dry it well then inject a small
quantity of oil used to mix fuel and rotate the crankshaft
several times to distribute the oil well inside the engine.
Finally reassemble the engine and store it in a dry place
after inserting it in a heavy vinyl bag.
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