O.S. Engines 2CK Carb - 22781010 - Manual (Page 2)

(b) If instead of being set too rich, the Mixture Control Screw
is set too lean, the engine will stop when the throttle is closed, or
will lose speed while idling and then cut-out abruptly (without
smoking) when the throttle is opened again. In this case, turn the
Mixture Control Screw counter-clockwise about 30 degrees, and
make sure that the mixture gets rich, then turn it clockwise
gradually.
Mixture Control Screw adjustment is not critical and by re-
membering the symptoms of rich and lean running quoted
above, it is a very simple matter to establish the best setting.
III. The Throttle Rotor Set-Screw is for establishing the mini-
mum idling speed. If the engine runs too fast with the throttle
closed, the Rotor Set-Screw should be turned counter-clockwise
to allow the throttle opening to be reduced.
SUBSEQUENT OPERATION AND CARE
Once the required settings have been established, it should be
unnecessary to alter them. Such slight needle-valve alterations as
may be necessary to cope with differences in atmospheric condi-
tions or fuels, do not affect the other two adjustments. The
engine should start readily with the throttle in the idle position.
It is important that the carburettor operates under clean condi-
tions. Make sure that fuel is properly filtered before use. We
advise fitting a filter to your fuel can and another filter in the
delivery tube between tank and engine, to reduce the risk of the
carburettor jet becoming partially clogged and upsetting running
adjustments. Remember to clean the filters periodically.
If, despite the use of filters, foreign matter should reach the
carburettor, causing it to malfunction, it should be carefully
dismantled and cleaned as follows:
( 1 ) Remove complete carburettor from engine. Clean off any
external dirt.
(2) Remove throttle rotor set screw.
(3) Withdraw rotor from carburettor body, taking care not to
lose the rotor spring placed behind rotor.
(4) Remove needle from needle-valve assembly, followed by
hexagonal retaining nut and ratchet spring. Now push
nozzle unit through body from outside.
(5) Remove fuel inlet nipple.
(6) Immerse parts in solvent (e.g. gasoline, alcohol or carbon-
tetrachloride) and clean thoroughly.
(7) Re-assemble in reverse order. Note that periphery of nozzle
flange is specially shaped to key into carburettor body.
PARTS LIST
Description
Carburettor complete
R/C Needle valve assembly
Rotor stop set-screw assembly
Throttle lever
Rotor spring
Throttle lever fixing nut
Throttle fixing screws
Carburettor rubber gasket
Mixture control screw
Nipple
5, ^ 3 - K Code No.
2B
22681005
22681908
22681306
22681419 22481410
22481506
22481420
25081700
22615000
22481628 22481628
22681953 22681953
2CB-D 2CK
22481040
45181919
22681306
22481506
22481420
25081700
22615000
22781010
22681908
22681306
22781411
22481506
22781420
25081700
22615000
22781601
22681853
The specification are subject to alteration for improvement without notice.
6-15 3chome Imagawa Higashisumiyoshi ku
Osaka 546, Japan T E L Osaka (06) 702 0225
© Copyright 1988 by O.S. Engines Mfg. Co., Ltd. All rights reserved. Printed in Japan