O.S. Engines 20B Carb - 23818030 - Manual (Page 4)

Mixture Control Valve
Carburettor Body
Fig.3
BALL LINK AND SLIDE VALVE EXTENSION
When readjusting the position of the Ball Link,
always apply a 6mm spanner or wrench to the flats
on the Slide Valve Extension, before attempting to
loosen or tighten the ball link retaining screw. Care-
fully ease back the Dust Cover bellows to allow access
to the flats. If it should become necessary (e.g. for
cleaning) to disassemble the throttle parts, first
unscrew the Slide Valve guide screw and withdraw
the complete sub-assembly from the carburettor
body. Use the correct size (8mm) wrench when
unscrewing the Slide Valve from the Slide Valve
Extension. See Fig. 2 and parts drawing (below).
REALIGNMENT OF MIXTURE CONTROL VALVE
In the course of making carburettor adjustments, it
is just possible that the Mixture Control Valve may
be inadvertently screwed in or out too far and there-
by moved beyond its effective adjustment range.
Its basic position can be found by first rotating the
Mixture Control Valve until its .slotted head is flush
with the carburettor body. The valve is then screwed
in exactly 1 turn (20B carburettor), or 3 turns (20A
carburettor), to establish its neutral position. See
Fig. 3 (above, left).
Then screw the valve in exactly 1 turn
(20B carburettor), or 3 turns (20A
carburettor).
1. mm (20 A)
0.5mm(20B) 2 turns
1 turn
First rotate the Mixture Control Valve
until its slotted head is Hush with the
carburettor body
PARTS LIST
Description
Throttle Stop Screw (w/spring)
Mixture Control Valve Assembly
"0"Ring(L) for Mixture Control Valve
"0" Ring(S) for Mixture Control Valve
Needle Valve Assembly
"0" Ring for needle
Universal Nipple No.9(w/sealing washer)
Carburettor Body (fitted with Thermo-lnsulator)
Slide Valve Guide Screw
Carburettor Rubber Gasket
Carburettor Sealing Washer
Slide valve
Metering Needle Assembly (w/spring)
Slide Valve Extension
Dust Cover
Ball Link No.1
Code No.
20A
23818500
23818180
46066319
22781800
23818150
46066319
23818176
23818100
45581820
29015019
23818190
23818201
23818300
23818211
22884210
23818400
20B
23818110
23818251
23818310
The specifications are subject to alteration for improvement without notice.
6-15 3-chome Imagawa Higashisurniyoshi-ku
Osaka 546, Japan. TEL (06) 702-0225
FAX (06)704-2722
© Copyright 1995 by O.S. Engines Mfg. Co., Ltd. All rights reserved. Printed in Japan 60130180 29507