Content .. 192 193 194 195 ..

Defender 90 / 110 / 130. Manual - part 194

EL SYSTEM

59.

Assemble the jet to the bi-metal jet lever and

ensure that the jet head moves freely in the
cut-out.

60.

Fit the jet and bi-metal jet lever to the carburetter

and secure with the spring loaded jet retaining

screw.

61. Fit the mixture adjusting screw.

62. Adjust the mixture screw until the jet is flush with

the carburetter bridge, then turn the screw a
further three and one half turns clockwise.

63. Using

a new sealing ring, fit the float chamber

cover, noting that it can only be fitted o n e way.
Secure with the four screws and spring washers and
evenly tighten.

Fit piston

and

suction

chamber

64.

Fit the needle, spring and

assembly to the

piston ensuring that the etched arrow

needle locating guide is aligned between

t h e

piston

transfer holes, as illustrated.

65. Secure and ensure that when

the

screw is tightened

the guide is flush with

piston and that the screw

locates in the guide slot.

66. Fit the piston key to the carburetter body using

new screw. Tighten

scrcw and splay

t h e

67. Fit a new suction chamber sealing ring

to the

carburetter body.

68. To

prevent the piston spring being ‘wound-up’

during assembly, temporarily

fit

piston

and

suction chamber less the spring to

body, and

pencil mark the relationship of the chamber to the

body. Kcmove the suction chamber and

fit

the

spring to

piston. Hold the suction chamber

above the spring and piston, align

pencil marks

and lower the chamber over the spring and piston,
taking care not to rotate the suction chamber.
Secure the chamber to the body with the three
screws, tightening

and check that the

moves freely.

69. Hold the piston at t h e top of its stroke and

fit

the

spring clip.

70.

Fit

t h e

piston

71.

Using a new joint washer, fit

t h e

air

intake adaptor

and secure with the two nuts and spring washcrs.
Fit

carburetters to the inlet manifold ensuring

that

joint washers, dcflcctor and insulator are

fitted in

sequence illustrated. The insulator

must be fitted with

arrow

uppermost and

pointing inwards towards the manifold. Secure
with the four nuts

spring washers and tighten

eveniy

the correct torque.

A .

Joint washer.

Deflector-teeth pointing inwards.

Joint washer.

Insulator.

E. Joint washer.

continued

FUELSYSTEM

MODEL

CARBURETTER

S.U.

SPEC

EXHAUST CO

EXHAUST

IDLE SPEED

PART No.

No.

(NEW ENGINE)

(After

km)

R.P.M.

TUNE AND ADJUST

SU HIF 44 CARBURETTERS

Special tools:

Carburetter balancer 605330 or

B89

Non-dispersive infra-red exhaust gas analyser.

IDLE

SPEED R.P.M.

C D

ALL HICOMP
ENGINES

General Requirements Prior to Tuning Carburetters.

Accurate  engine  speed  is  essential  during  carburetter
tuning,  therefore  the  distributor  pick  up  air  gap  and
ignition  timing  must  be  checked  together  with

vacuum advance system.

Whenever possible the ambient air temperature of the
tuning environment should be between

15" to 26°C

80°F). When checking engine speed, use an

F X

2 0 0 6

ETC7 123

independent and accurate tachometer.
Idling adjustments should be carried out on a fully

thermostat has opened. This should be followed by
run

of one minute duration at an engine speed

approximately

2,500

before

further

adjustments or checks are carried out. This cycle may
be repeated

often

required. It is important that

the

above cycle is adhered

to,

overheating

may result and settings may be

The piston

dampers  must  always  be  kept  topped-up  with  the
correct grade of oil.
Before  any  attempt  is  made  to  check  settings  a
thorough  check should be carried out

that the

throttle linkage

the pedal and carburettcrs is

free and has no tendency to stick. Ensure that the
choke control lever is pushed fully down.
NOTE: References to left and right hand are as from the
drivers seat.

hollow piston rod.

74.

and adjust the carburettcrs.

TAMPER

PROOFING

T o comply with

E.C.E. regulations the idle

and

mixture adjusting screws must be tamper

following any adjustments.

red blanking plug; Part

number

JZX 1258 must be fitted into

mixture

screw

and

a red cap; Part number JZX 1197

fitted over the idle adjustment screw (throttle
adjustment

ALL HICOMP
ENGINES

continued

F X

2 0 0 6

ETC7 123

ALL UCOMP
ENGINES

ETC7 124
ETC7 I25

ALL UCOMP
ENGINES

ETC7 124
ETC7 I25

600 - 700

1100

NEW ENGINE

700

800

600 - 700

NEW ENGINE

700

800

RUN

-IN

FUEL SYSTEM

The following instructions apply to both carburetters
unless otherwise stated.

Before commencing the following instructions, remove
the air cleaner, air intake elbows, mixture adjustment

screw plug and mixture screw cap.

CARBURETTER BALANCE

Using balancer 605330

Disconnect the interconnecting link betwccn the

two carburetters. Fit the balancer

to the

carburetter intakes and ensure that there are no air
leaks, i f necessary, zero the gauge with t h e
adjustment screw.

Start the engine, and if necessary allow

to reach

normal operating temperature. If t h e needle moves
to the right, decrease the air flow through

t h e

hand  carburetter  by  unscrewing  the  idle  screw.
Alternatively,  increase  the  air  flow  through  the
right  hand  carburetter  by  screwing  down  the  idlc

screw. Reverse the procedure if the pointer moves
to t h e left. Reconnect the carburetter inter-
connecting link.

Using balancer I389

3. Disconnect the inter-connecting throttle link

Back-off

t h e

idle adjusting screw

on each

5 .

Turn

each throttle adjusting screw so that

equal amounts to achieve an approximate idle
speed of 700 to 800

6 . Press the balancer firmly

the

intake. Press or withdraw the control on the side of
the balancer

adjust the meter needle reading to

approximately half

and note the reading.

t h e

two carburetters.

carburcttter,

of the throttle lever.

touches

the

continued

FUEL

YSTEM

7. Without altering the position of the balancer

control, place the balancer on the second
carburetter intake and adjust the idle screw as
necessary to achieve the same reading.

8. Alternatively, adjust and check the balance of both

carburetters

until

an idle speed of 700 to

800

Reconnect the throttle inter-connecting link, and

again check the idle speed and balance.

Mixture

setting

Ensure that the

is still at normal operating

temperature.

Mark the

of the suction chamber to

carburetter body, remove the retaining screws and

lift

off

suction chamber complete with pistons.

12.

achieve a datum setting for the mixture screw,

turn

i t

anti-clockwise until the jet is level with the

carburetter bridge. Check by placing

a straight

edge across the bridge and adjust as necessary

that the jet just touches the straight edge.

13.

t h e

suction chamber and piston, evenly

tighten the retaining screws. Check that the piston
moves freely without sticking. Top-up the piston
damper.

14.

Turn the mixture adjustment screw three and one
half turns clockwise.

15. Insert the probe of an infra-red exhaust gas

analyser as far

possible up the exhaust pipe, start

the engine and allow a one and one half minute
stabilisation period.

16. Adjust the mixture screw on both carburetters by

equal amounts, rich

or weak to achieve a C O

t o

2.5%.

17.

after approximately two minutes

level is

not satisfactory run the engine at 2000

for

one minute

to stabilise the

the

setting procedure until a stable C O reading of 0.5
to

2.5% at an idle speed of 700-800

obtained.

speed

and

18. Check that the engine is at normal operating

temperature.

19. Slacken the nut, at t h e left hand carburetter

securing the inter-connecting link ball to the
throttle cam lever.

ST18 8

continued

Content .. 192 193 194 195 ..