O.S. Engines 86 Carb - 27881000 User Manual

Page 2

out readjustments progressively and patiently, re-
membering the symptoms of rich and lean running,

quoted above, until the engine responds quickly and

positively to the throttle.

4) The Throttle Stop Screw is for f i x i n g the minimum

idling speed. If, after carrying out mixture adjustments,
the idling speed is found to be too high, the Throttle
Stop Screw should be turned counter-clockwise until
the desired idling speed is obtained.

Note: Once the correct carburettor settings have been

established, it should be unnecessary to alter them.

Such slight needle-valve readjustments as may be
required to compensate for variations in atmospheric
conditions will not normally affect the other two
controls. Slight readjustments may be necessary for

optimum performance if different types of fuel,
glowplugs or propellers are used.

CARBURETTOR CLEANLINESS
The correct functioning of the carburettor depends on its

small fuel orifices remaining clear. The minute particles of
foreign matter that are present in any fuel can easily partial-

ly obstruct these orifices and upset mixture strength so that

engine performance becomes erratic and unreliable.

It is recommended that fuel is passed through a filter when

the tank is filled and that a good in-line filter is installed
between the fuel tank and carburettor and, furthermore,

that this filter is frequently cleaned to remove dirt and lint
that accumulates on the filter screen. Finally, occasionally
remove the needle-valve holder from the carburettor and

extract any remaining foreign matter that may have lodged

inside the carburettor.

Dirand fibrous matter

mostly accumulate here

PARTS LIST

Photo 2

Description

Throttle Lever Assembly (with screw 8 lock washer)

Carburettor Rotor

Throttle Stop Screw Assembly

Throttle Stop Screw

Throttle Stop Screw Holder Ass'y

Carburettor Body

Carburettor Rubber Gasket

M i x t u r e Control Screw (with spring)

Plug Screw (with washer)

Fuel Inlet (with washer)

Mixture Control Valve Stopper (with spacer)

Nipple (with washer)

Mixture Control Valve Assembly

"0" Ring (S)

"0" Ring (L)

"0" Ring

Needle Valve Assembly

Needle Valve Holder Assembly

Ratchet Spring

Needle (with "0" ring & set-screw)

"0" Ring

Set-screw

The specifications are subject to alteration for improvement without notice

Code No.

27881400

27881200

27181600

27181620

27181610

27881100

29015019

27881330

27881120

22681953

27681340

22681953

27881300

27881800

27881810

27881820

27681900

27381940

26711305

27681970

24981837

26381501

6-15 3-chome Imagawa Higashisumiyoshi-ku

Osaka 5 4 6 , J a p a n . TEL (06)702-0225

FAX. (06) 704-2722