If the engine starts to run backwards do not open the throttle - stop the engine immediately! Otherwise
the engine can be damaged!
Step I
Accelerate to 2/3 of the throttle range within approx. 1 sec (faster acceleration). Repeat three
times – if the engine accelerates quickly and without a hiccup go to Step III. If acceleration is not smooth go
to Step II.
Step II
Faulty acceleration with hiccups and a tendency to cut out is usually attributable to a poor fuel
mixture in the medium-revolutions range. Stop the engine and recheck the fuel feed (the hose-pipe must not
be pinched or broken; if fitted, check also the fuel filter permeability). Restart the engine and test
acceleration again. If problems persist adjust the carburetor. Open the adjusting needle L by 5 min and retest
acceleration. If acceleration is smooth, open the needle by another 3-5 min - this should be done because the
needle was previously set at a boundary value; if atmospheric conditions changed during flight, the
problems might recur.
If the engine still has bad acceleration, open the needle by 10 min (60 degree). If the engine’s
operation does not improve afterwards, stop it and check the basic setting. Set the adjusting needle L at 1
turn and 50 min and the adjusting needle H at 1 turn and 10 min. Restart the engine again and test
acceleration. If the engine runs correctly go to Step III. If engine does not accelerate properly, open the
needle by another 10 min. If it does not accelerate, the defect supposed to be elsewhere than in incorrect
adjustment. In this case go to the section on problem solving.
Step III
If the engine accelerates correctly, according to the above test, set it at idle speed and accelerate
to full speed. Repeat twice more. If the engine functions correctly, go to Step IV. If it cuts out, open the L
needle by 5-10 min more.
If the engine does not respond to acceleration fast enough keep closing the L needle until the
engine starts to cut out in response to gas. At that point reopen the L nozzle by 5-10 min.
Step IV
If the engine reacts correctly set it at full speed. If revolutions do not drop, the engine has been
adjusted successfully. If revolutions seem to drop, open the adjusting needle H by approx. 5-10 min.
Caution!!!
The engine must be stopped while you adjust the carburetor in order to prevent injury by the propeller.
Never close the choke valve completely when the engine is operating!
The choke valve is set to allow minimum air flow only when fully closed, which could cause damage to the
intake reed valve.
Depending on the throttle control used
there is a possibility to use throttle
stop-screw.
If the throttle pull rod is not equipped
with
flexible
element
it
is
recommended NOT to put off the
throttle valve spring. Otherwise the
vibrations of the engine can cause
excessive wear of the throttle valve
shafting and with this deteriorate the
carburetor function.
Adjusting carburetor position
You can turn the rear cover by 90
°
which makes it possible to adjust the carburetor’s position (especially its
adjusting needles) when fixing it in the model.
How to dismantle the rear cover:
Unscrew two M4 screws that hold the carburetor in place, remove the pressure hose from the carburetor
(mind the gasket under the carburetor), remove the carburetor and loosen four M5 screws along the
crankcase (Caution! Do not loosen the M4 screws that fix the reed-valve to the rear cover).
Remove the rear cover by pulling it out of the crankcase – never use a hammer or any other similar tool.
The rear cover is sealed in the crankcase with two sealing rings – therefore more strength is needed,
however, it must always be pull only!
Make sure you disassemble the engine in a clean environment!
Position the rear cover as desired, carefully insert it in the crankcase and tighten the screws. Do not forget
insert the gasket when reassembling the carburetor.
Starting and running in a new engine
Before you first start the engine, screw the plug in and tighten it up. Follow the instructions on the box of
the spark plug. Make sure that the plug socket is fitted in place and fastened down properly; pull the wire
ring over the hexagon. Fix the ignition sensor in proper position above the magnet with screws enclosed.
Unless the spark plug is not inserted in plug socket, never turn the engine with ignition turned on. This
could lead to ignition damage!
1) Make sure that the ignition is switched off, the choke valve is closed and the throttle valve is about half
opened. Then give the engine 3-4 turns, provided that carburetor is not overflowing. If it is overflowing,
only give the engine 1-2 turns.
2) Switch the ignition on, open the choke valve, set the throttle at slightly higher idle speed and give the
engine a few quickly turns. If even after the fourth turn, with the choke valve closed, you do not hear a
suggestion of the engine starting, give the engine 2 turns following the instructions in paragraph 1 above.
Then proceed according to instructions given in paragraph 2.
3) If the engine does not start even after another set of turns open the throttle to maximum and give the
engine approx. 4 turns. Switch the ignition off and on again and restart the engine with throttle turned
slightly down and the choke valve set open.
4) If the engine still would not start, unscrew the plug and check its contacts. Clean any possible petrol
moisture (i.e. an indication of engine overflow) and screw it in again. Further starting should only be done
with the throttle turned down. If the plug is dry then probably not enough fuel has been drawn into the
carburetor. If that is the case, check the fuel feed and then return to the instructions given in paragraph 1.
If the engine starts to run backwards do not open the throttle - stop the engine immediately! Otherwise
the engine can be damaged!
Having started the engine, leave it running for approx. 2 min at a higher idle speed. Then run it in for
approx. 20 min, while changing revolutions from idle to 1/2-3/4 of the range and shortly holding each
position - gradually prolong the holding periods. After 10 min of operation start opening the throttle at
maximum for short periods of time. Stop the engine and let it cool down. Then restart it and check the
adjustment. If everything is all right, you can first take off. During first few flights do not overload the
engine and do not let it run at high revolutions for long periods of time (very important at hot weather). Use
up all fuel that was produced as a mixture with the oil that is included in the package. From now on, fuel
and oil should be mixed in the proportion 40:1.
•
DO NOT PROCESS THE RUNNING-IN AT IDLE SPEED!
•
A COLD ENGINE SHOUL BE WARMED UP BY SHORT ACCELERATIONS (1-2 SEC)
Throttle stop
screw
Throttle lever
spring
