MOTO GUZZI 700 cc Twin V-7 User manual

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MOTOGUZZI
rider's handbook

~
MOTO GUZZI
FACTORY AND OFFICES:
Meodello dItI urio (Como)
VI, ElNnue'- V. Parod i, 57
Telephones:
.¥..ndello ~I lario 71 .112 (4 lines)
Telegram5:
MOTOGUUI • Mar'ld&llo Lorio
HEAD OFFICE: Vi, Andegarl, ..
felephone: 890632
BRANCH OFFICE:
Mil,,"
Vi, Domodossola, 17
Telephone: 311 .105
Nlpl ...
Piana MuniciplQ, 8"
Telephone: 310.581
Telegraml: MOTOGUUI _ Naples
700
cc
TWIN
v -7
MODEL
RIDER'S
HANDBOOK

INTRODUCTION The purpose of this booklet is to provide
ownen with the necessary information on
operating and maintaining their machines for
maximum efficiency.
2
This manual should be read very carefully
as most troubles and fail urn arising from
neglec;t or poor maintenance will be avoi-
ded if all the instructions herein contained
are strictly followed.
Dont forget
thai all major overhauls and re-
pairs are best carried out by officially ap-
pointed Mota Guzzi dealers who have the ne·
cessary facilities required to competently re-
pai r your Moto GUlli.
INDEX Running in
Controls and accessories
Identification
data
Igni tion key
Tool kit
Spare
parts
Main features
Instruments ilnd controls
Riding
instruct i ons
Lubrication and genenl milinten .. nc e
Servicing instruct ions .
Lubrication of engine
Oil pressure relief valve
Oil
pressure gauge
Lubrication of transmission
Lubrication of
rear wheel drive
Lubrication of front f
ork and hy_
draulic dampers
lubrication of bevel gears in steering
Lubrication of wheel bearings
Lubrication of control cables
Lubrication of rear fork bearings
C .. rburation
Filters and fuel lines
Carburetor
Standard carburetor settings
Adjustment for idling speed
Determining correct size of main jet
Stripping
of carburalor
Air filter
Fuel
tank
pag. 5
• 6
• II
• II
• II
• II
• 13
• 18
• 21
• 26
• 28
• 28
• 28
• 28
• 28
• 30
• 32
• 32
• 32
• 32
• 32
• 33
• 33
• 34
• 34
• 34
• 36
• 37
• 38
• 38
3

,
Mufflers
Valve ge aring
Ta.ppet ciea.rance
Valve
tim ing
Ignition
Distr
ibutor
Spark plugs
Ignition timing
Adjus
tm e nt s
Generator belt
Clutch lever
Steering
Front
brake lever
Rear
brake pedal
Rear suspension units
Removal of
front wheel
Removal of rear wheel
El eclriCilI equipme nt
Battery
Generator
Regulator unit
Starter motor
H orn
Light switch, dipper switch and
horn button
Headlight
Bulbs
Tail light
Fuses
Cables
pag. 39 Running
in
• 39
• 39
• '0
·"
·"
·"
·"
• 45
• 45
• 45
• 45
• 46
·"
• '9
• 50
• 51
• 5d
• 5d
• 55
• 55
• 55
• 56
• 56
• 56
• 56
• 56
• 56
• 56
During the first 1600 kms. (1000 miles) a
new or overhauled machine should be used
intelligently since the efficiency,
performance,
a.nd life of the engine are largely dependant
on how it is used.
The englne
should never be allowed to reach
a high
number of revolutions before it has
had a chance to sufficiently warm up.
Never ride the machine
at the highest speeds
permitted for each gear before the machine
has been well broken in.
Should the engine speed drop off considerably
on an uphill grade, a lower gear
should be im.
mediately engaged. In case of overheating, it
is best to stop the engine and allow it to cool
down.
Under
no circumstances whatever should the
Following speeds be exceeded while a machine
is being run in.
Maximum permissible speed:
Distance covered:
Up to 800 kms. (500 miles) :
in low gear
in second gear
in third gear
45 (28 miles)
65 (40.5 miles)
85 (53 miles)
in high gear 110 ( 68 miles)
From
800 to 1600 kms. (500 to 1000 miles) :
in low gear 55 (34.5 miles)
in second gear 80 (50 miles)
in third gear IDS (65 miles)
in high gear 135 (84 miles)
From 1600 to
3000 kms. (1000 to 1800
miles) :
Gradually increase the speed up to the ma-
ximum permissible limit.
5

After th e first
500 kms .
(
300 miles )
Ev ery
500 km s.
( 300 mil es )
Change the engine oi l.
Tighten all nvts and bolts.
Check valve clearance.
Check distributor contacts gap.
Check oil level. Correct level is in between
the
minimum and maximum mark on the
Filler
cap dipstick.
CONTROLS AND ACCESSORIES
(See fig. I)
,
I Front brake lever
2 Air control lever
3 Throttle control grip
4 Fuel filler cap
5 Gearshift lever
6 Pillion footrests
7 Pillion handgrip
8 Headlight
9 Speedometer
and lighted indicators
JO
Key type ignition switch
II
Clutch lever
J2 Dipper switch
il nd horn button
J3 Side stilnd
14 Reilr brilke pedill
IS Footrests
16 Center stand
17 Tail lamp
N.B. _ The te rm, .. right It an d " le fl It in th e lui
a .. Ul ed in 11M o.e nH th ey would op pea r to On e
l i ll ing in the .... dd l e.
fig. 1 7

• •
.! •
•
.>
--
-
•
~
~
~
"
N ..,
..
;;:
..
;;:
8 9

Fig. 4
10
IDENTIFICATION DATA
(See fig. 4)
Ignition key
TOOL KIT
(See fig. 5)
SpOU $ p ll Tt$
Every machine is identified with ill serial num
ber which is stamped on the frame down
lube and on the left hand crankcase cover.
An ignition key and II duplicllte are supplied
with each machine, The number should be
recorded. In case of lou, the key number
should be reported 10 your dealer.
1
~ So)!. wrench, 19/ 21 /22
mm .
2 Open
ended wrench, 17 /19
mm.
3 Open
ended wrench, 10/ 11
mm.
4 Tappel
adjus ting wrench
5 Box wr
ench, 8/ 9 Mm.
6 Allen key
(5 hex)
7
Box wrench, 10/14 Mm.
, Universal
pliers
9
Adjustable wrench
10
Screwdriver
11
Ring wrench, 27 Mm.
12
-Tool bag
If replaceme nts are required be sure thaI
genuine Moto GUlzi paru iJre used. Failure
to do so will absolve the Manufllctvrer fr om
all guarantee liabilities.
"

Fi g. 5
12
Fig . 5/ 1
MAIN FEATURES
ENGINE
(See fig. 5/1)
Valva gear
Cycle 4 strokes
Number of cylinders : 2
Cylinder disposition: «V • . 90"
Bore 80 mm. (3.149")
Stroke
Displacement
70 mm. (2.755")
703.717 CCo (42.93 cu.
in.)
Compression ratio 9 to 1
Revs at ma x engine
speed 6000 r.p.m.
Output at max
engine speed 50 HP SAE
Crankcase
Cylinders
Cylinder heads
in light alloy
in
light alloy, hard
chromed bores
in light alloy, hemi-
spherical, with special
cast iron inserted valve
seats
Crankshaft steel cons t ruc tion
Crankshaft supports : in special lin-aluminium
Conne<:ting rods
Pistons
alloy pressed in suita-
ble housings
steel construction with
AL·TIN alloy thin wall
bearings
in light alloy
O.H.V., push rod operated via the camshaft
in the crankCi,lse and gear driven by the
cr.,nkshaft.
Inlet;
opens 24' before TDC
-closes 58 " .,fter SDC
13

Carburation
Lubrication
Coo li ng
Ignitio n
14
Exhaust :
-
opens 58· after BDC
-closes 22· after TOC
Rocker clearam:e for valve timing:
-0,5 mm. (.0196")
Normal rocker clearance (cold engine) :
in let 0.1 mm. (.00393")
-exhaust 0.2 mm. (.00787")
Both carburetors are gravity fed from th e
tank.
Carburetor Make:
type Dell"Orto 5.5 .1 . (ringh t and left)
Pressure,
by gear pump driven by the crank-
shaft.
Oil strainer in crankcase.
Normal lubricating
pressure 2.5 -3 kgs./sp.
crn. (35.6· 42.7 Ibs/sp . in.)
(Controlled by relief valve)
Electrically controlled oil pressure gauge.
By air . Cylinder and cylinder heads deeply
finned.
8y battery with automatic advance Marelli di-
stributor type 5 123 A.
Inilial advance: 10 ·.
Automatic advance: 28°.
Ignition timing 38" full advance.
Contact
breaker gap: 0.42-0.48 mm.
(
.016-.018").
Spark plug : n. 225 in Bosch-Marelli scale or
equivalent.
Exhau st system
TRANSMISSION
Clutch
Gear box
Seconda ry drive
at rear wheel
Plugs point gap : .6 mm. (. 023") .
Ignition coil: Marelli
BE 220 O.
Marelli stuter MT 40 H (12 V- .7 HP) with
electromagnetic ratchet control. Ring gear
bolted on flywheel.
Dual e~haust pipes and mufflers.
Twin driven plates,
dry type, located in the
flywheel. Controlled by lever on left han-
dlebar.
Four speeds, frontal engagement. Constant
mesh gears. Cush drive spring incorpor<Hed.
Separate case bolted on crilnkcase, operated
by r ocker pedal on the right hand side of the
machine.
Engine-gearbox
ratio:
I to 1.352 ( 17-23)
Internal gear ratios:
Low gear
'0
1.812 ( 16-29)
Second gear w 1.25
(20-25)
Third gear w 0.956
(23-22)
High gear
'0
0.730
(26-19 )
By homokinetic double joint cardan shaft.
Bevel layshafl gear-wheel ratio: 4.625 (8·37)
Overall gear ralios :
Low gear
'0
11.330
Second gear
'0
7.816
Third gear
'0
5.977
High gear
'0
4.564
15

FRAME
Tires
Tire
pr en ure
O ye r ~ dl
dimensions and
weight
Pe rforman ce
16
Duplex cradle, tubular 5!ruclure.
Telescopic front forI< incorporating hydraulic
dampen.
Rear swinging fork with external adjustable
springs.
4.00 x 18 front and rear, block type 0: high
speed
".
Front:
solo rider kgs./sq.cm. 1.5 (21 Ibs/sq.in.)
with pillion .. 1.5 (21 Ibs/s q,in .)
rolo rider .. 1.8 (26 Ibs/sq.in.)
with pillion .. 2.0 (29Ibs/sq.in.)
Twin leading shoes eJlpanding type front bra·
ke operated by hand lever on the right han.
dlebar.
Large rellr brake operated by pedal on leff
hand side of machine.
Wheelbll5e 1.445
Length 2.230
Width 0.795
Height (dry) 1.050
-Minimum ground
clearance. 0.150
Dry weight
mlS. (ab!. 56.9")
mls. (ab!. 87 .8 " )
mts. (ab!. 31.2")
mts. (abl. 4 0.3")
mlS. (ab!. 5.9")
. 490 Lbs.
Maximum permissible speeds and gradients
climable in each gear, solo riding:
Low gear ab!. 66 kms /h 41 m.p .h.)
Climbing ability 60 %
Second gear
.. 96 kms/h 59.6 m.p.h.)
Climbing ability 34%
Third gear • 120 kms/h 74.5 m.p.h.)
Climbing ability 23 %
Reple nishmen ts
High gear • 170
kms/h (106
m.p.h.)
Climbing ability 14%
Fuel
tank 20 liters (7.57 US gls.) Petrol
98
NO (Regular octane) . Sump 3 liters (3*
Quarts) Shell Multigrade 20/40 . Transmh·
sion 0.750 liters (Ii Pints) Shell Spiru 90
E. P .. Rear whell drive 0.300 liters (5/8
P ints) Shell Spirax 90 E.P .. Fr on t fork dam.
pen 0.160 liters = 5,4 0% USA c Shell Tellux
33 •.
d
Fig . 6
17

INSTRUMENTS AND CONTROLS
\8
1 - Speedometer (See fig. 6) including
II) Mile calibrated clock.
b) High beam indicator red lighl;
c) Red warning light, ammeter. Indica-
ting insufficient flow of current from
generator for battery charge. Should
go Oul when engine has reached a
certain number of revolutions.
d) Orange warning light. Neutral indica-
tor. Does not lighl up when /lny gear
is engllged.
e) Red warning light. Oil pressure gauge,
Goes OUI when there is sufficient oil
pressure for engine lubrici!llion.
2 - Ignition key switch (Automotive type).
This controls the entire eleclric equip-
ment lind engine SllIrting. This key has
Ihe function of lin antitheft device (See
fig.6),
This key hllS four positions :
« 0" = Machine III standstill, key re-
movable, all electric! switched
o ff .
• 1 :0 = Machine standing, key remova·
vable,
parking lights on .
• 2 ,. Running position or machine
ready to set OUI. All controls
on. For daylight riding no other
position is necessary.
For night driving lever A 00
the left handlebar switch must
be switched on.
For SUlrting ooly. The key reo
turns automatically to position
2 when the engine has started.
3 - Clu\o;h lev er
It is locaied on the left hllnd handlebar
and should be used only for starting and
gear shifting.
<I _ Twist g rip thrott le c:o ntrol
It
is fitted on the right handlebar. Throt -
tle is opened by turning towards the
rider.
Fig. 7
"

20
5 - Air le ve r for carburetor s
6·
7 .
8 .
9 .
Pulling this towards the rider opens the
air and viceversa closes or chokes the air.
Front brake lever
It is located on the right handlebar .
Dipper switch
and horn button (see
fig. 7). On left handlebar .
Switch A:
POsition 1 =
Position 2
Switch B:
lights off
lights
on
Position 3 = low beam
Position 4 = high beam
Push button C = horn control.
Gearshift lever
Of rocking type, on right hand
side of
machine.
Re
ar brake pedal
It is located on the left hand side of the
machine.
RIDING INSTRUCTIONS
Engine
s tarting
Import ant
notice
Ensure there is sufficient oil in the tank and
the crankcase oil is at correct leve\. (nsert
the ignition key
and switch it on to pOSition 2
(See fig. 6), ensuring that the oil pressure
gauge, ammeter, and orange neutral indicator
light up. (Dont forget that when this latter
does not light up it means a gear is e ngaged) .
Attempting to
star t an engine in gear is be
dangerous, unless the clutch lever is kept ful-
ly disengaged, as with the firing of the en-
gine the machine itse lf might start off.
On a cold engine, the air lever is set in the
almost fully closed position and the gas ope-
ned about 3/4 turn. Turn on the ignition
key ful ly
to the right (See 3, fig. 6) to start
the engine. When the engine starts release
the key which will return to position 2 and
open the air lever gradually.
Under no
circumstances whate v er mus t t he
engine be accelerated immediately after it is
started. Al!ow it to idle for a few minutes in
the hot season and for a longer time in cold
weather in order that the oil may reach all
lubricating points or until the cylinders
stan
getting warm.
Even at very low temperatures, the engine
should always start easily provided it is in
good running order and sufficient thrust is
imparted by the sta-rter motor. If the engine
does not star t easily, do not persist in many
attempts, but check carburation, ignition, bat -
tery charge, and ensure that the oil is not
too heavy.
21

Starting
a hot
engine
Starting ,
!letting
und er way ,
a
nd stopping
the machine
Starting
On th e way
"
When sHirting a hot engine there is no need
to close the air lever lIS this would (ichen
the mixture lind mllke stllrting difficult. When
engine
starting is difficult due to being over-
heated, open the
throttle grip completely and
at the Sillme time switch on end off the igni-
tion key from the .. 3 • position.
Pull the clutch lever fully, engage bottom
gear, release the clutch slowly, and turn on
the gu simultaneously.
As soon 11$ the engine picks up some speed,
close the gllS, pull the clutch lind by down-
ward toe pressure engage second speed. Re-
le"se then the clutch lever rllpidly (but r,ot
with a
jerk) and turn on the gas once more.
Third lind high gellrs lire likewise eng"ged by
toe
pressure.
In norm,,1 riding conditions, 1111 tell-tale lights
in the speedo
should be off. If IIny one is
Iii up, there is either some fault in the
system or oil pressure is insufficient. Steps
must be taken immediately to locate and cor-
rect the fault.
The maximum speeds in each gear should
never be e~ceeded, not even on steep downhill
grades. Dont forget that by toe pressure you
pass to a higher
gear and by heel pressure to
a lower
gear (See fig. 8).
Before any gear is engaged, mllke sure the
dutch is always completely disengaged. It is
necesSiliry to fully dose the gas when you
change up but il can be closed partillily
when changing down. To obtain fillst lind
effortless gear shihs, always depress the pe-
dal firmly but gently withOut stamping or
jabbing vigorously.
The free position (neutral) is in between first
Stopping
the machine
ilInd second gear. To locllte this position it
is necessary
to shift 10 bottom gear lind then
by slight toe
pressure (haM stroke). To feel
for neutral position.
With the mllchine
standing still and the en·
gine running, the transmission should "lwillYs
be kept in neutral. Do not keep the clutch
lever
depressed even during the briefest stOps.
Always change to II higher ge"r rather than
let the engine race.
As soon as the mllchine stops, close the t hrot-
tle shift to neutral, turn the ignitiOn key 10
Ih~ «0. position and remove (fig. 6).
Fig. 8
23

EllERY
'"
FIRST
300
EVERY 6 00
EVERY
""
EV ERY 6 000
EVERY 12000
2'
" 0 -
" 6. S
HE LL Mu ltOg , .... 20140
" O SH
ELL Sp,_ . 90 [ . P-
" O SHELL
R.",.. xA
OStlELL l-'lux 33

LUBRICATION AND GENERAL MAINTENANCE
(See Cha rt fig. 9)
Month ly
Periodically
A.ft er the first
500 kms .
( 300 miles )
Ev ery
1000 kms .
( 600 miles )
Ev e ry
3000 kms .
(
1800 miles)
Ev ery
10000 kms.
( 6000 m il es)
2'
1 • Check electrolyte level in battery (every 15
days In sum......). See • Battery. ,
2 • Check tire prenure with II 9/lUgeo5 noted on
p~ge 16.
3 . Replace the cr.nkcase oil. See • Engine lub ri.
ca tion •.
.01 • Tighten 1111 nuts and bolts.
5 Check lind adJuu lappel play, If necessary.
See «Tappet Adjustment •.
6 . Check and il necessary lop up oil level in
crllnkca .... Correct level is in bet_n ,.... mi·
nimum aoo m •• i mum marks on lhe dipstick.
See • Engine lubrication . ,
7 • Lubricate cable ends. See • LubrlCIITlon of
dutch, 'ront brake, and air cllbl,u •.
8 Rep lace oil in crankcase. See • E"5Iine lub.i-
," i on •.
9 Check lappet ,Jellrance. See • Tappe t clea-
rance '" .
10 ChKk aoo clean spa rk plugs. See .. spark
plugs '".
11 ChKk oil level in gearbo~ and if necesury top
up . See .. Lubrication of gear bo~ 0 .
12 Check oil level in transmiulon box lor lubri-
cation 01 bevel gears. If ne<:euery, top up .
1
J - Clean petrol cocks and filters, carburetor fil_
ter, and fuel lioe to carburetors _ See .. Car·
buration.
A.ft er the fir st
20000 kms.
( 12000 , miles )
14 _ Strip carburetor and check ,II part$. Using an
air jet, clean ou t all ducts. See • Carburation '".
IS Change gearbox oil. See • Lubrication 01 gear
box •.
16 Change transmIssion box oil. See .lubriel-
lion of t ransmiuion >0.
17 _ ChKk cleanliness and tightneu of all bauery
connections and smear t hem with vaseline. See
.. Sattery '" _
18 _ Clean generator commu t ator using a clean
cloth slightly moistened in pelrol. See • Ge-
nerator ,..
19 _ ChKk condltlon 01 wheel bearings and if still
efficient pack these wi lh grease . See • lubri-
cation of wheel bearings •.
20 Check conditiOn of steering bearings and if
still good, pack with grease .
21 Replace oil In fork inner tubes . See lubrica-
tiOl"l of fork.
22 Clean starter motor commutator using a clean
rag lightly mOistened in petrol .
27

SERVICING INSTRUCTIONS
Lubrication of
en gine
(See fig. 10)
Oil pr es sure
relief valve
Oil pressure
gauge
Lubrication
of tran sm i ssion
(See fig. 8)
Using the oil filler dipstick (A), check the
sump level every 500 kms. (300 miles).
Correct oil level is in between the minimum
and ma~imum marks. This check should be
made on a warm engine.
Every 3000 kms (1800 miles) change the
engine oil
(on II new or overhauled mllchine
this change should be made lifter the first
500 kms.) (300 miles). The oil should be
replaced when the engine is warm by unscre-
wing filler cap A and drain plug B. Allow 1111
the old oil to drllin, re-flt plug B, and intro-
duce new oil. QUllntity required: llbout
3 liters (3
1
/
.. quarts), o il recommendiltion:
Shell Multigrllde 20/40 .
Under no circumstances should this vilive be
tampered with liS it hIlS IIlrelldy been calibra-
ted lit the fectory f or II pressure ope rlltion
of 2.5/3 kgs./sq.cms. (35-42 Ibs. sq. in.).
The indicator light goes out when the pres·
sure is sufficient to open the contact of the
pressure operated solenoid.
If this light stays
lit, then the oil pressure
is incorrect. In such
cases,
stop the engine and inspect all passages
and oil lines to determine the cause
and
correct before running engine.
The oil in th is box must be checked every
3000 kms. (1800 miles). The level is
co rr ect when the oil is flush with the plug
hole. Change thi5 oil every 10000 kms.
(6000 miles).
Thi$ operation should be carried out a shorr
time after a ride when the oil is warm and
easily drained.
To change the oil proceed liS follows: uns-
crew filler
Clip B, level plug A, and drain
plug C under the bolt. When the old oil has
drained and plug C re·fltted, introduce fresh
oil through B unt
il it stllrls to lellk out from
level hole A, when both plugs can be re-
pieced.
Oil quantity
required: abl. 0.750 liters
Fig.
10
29

()3 /. Pints).
Oil recommendation: Shell Spir&~ 90 E.P.
lubrication of The oil level of this bo)( should be checked
rear wheel drive every 3000 kms (1800 mites).
(See fig. 11) The oi1s hould just skim the hole (A ). Change
the oil every 10000 kms.
(6000 miles) and do
this operation On a hot engine. Unscrew fitler
plug
B, level plug A and drain plug C. When
the old oil has drained refit plug C and intro-
duce fresh oil untit it starts seeping through
hole A.
30
Fig. 11
\
A
Fig. 12
31

Lubrication of
front fork iimd
hydraulic
dampers
(See lig. 12)
lubrication
of bevel gears
in steering
lubr ication
of whee l
bearings
Lub rication of
control cables
Lubrication of
rear fork
bearings
32
QUllntity required : about. 0.300 liters (5/8
pint I.
Oil
recommendation: Shell Spirax 90 E. P.
Every 20000 kms. (12000 miles), change Ihe
oil in Ihe fork lubeS. Proced as follows : Re-
move Ihe drain plug and washer (AI and
plug B. When Ihe oil has drained,
and drain
plug A replaced inlroduce fresh oil Ihrough
6. QuanlilY of oil for each fork lUbe: aboul
0.160 lilers (SA 02). Oil recommendalion
Shell Tellux 33.
Every 20000 kms.
(12000 miles) check con-
dilion of the steering bearings and pack with
Shell Retinllx A grease.
Every 20000 kms.
(12000 miles) check the
condition of these bearings
and pack with
Shell
Retinu A grease.
Every 1000 km
s. (600 miles) cle~m the cable
ends
and lubricate with Shell Relinax A grea-
se. ACluale the levers sev er al times 10 allow
s ome of Ihe grease to enter into the casings.
At the lime of a general overhaul il is well 10
inspect these bearings to ensure there is suf-
ficient grease. Grease recommendati on: Shell
Retinax A.
CARBURATION
filters and
fuel lines Every 10000 kms.
(6000 miles) or al any
time when fuel flow is irregular, Ihe fuel
line and fil ters should be inspected lind clean.
ed. Ensure lhe lines are not obstructed a.nd
that the tap and carburetor filters are perfec.
tly clean.
These
are besl cleaned in a petrol bath a nd
dried off with compressed air . Ensure that
Fig . 13
33

Carburetor
Standard
carburetor
se tting s
Adjustment
'0'
idling speed
(See fig. 13)
34
the lines hllve not hardened at their connec_
ting ends. In such case, the lines should be
replaced with originlll equipment.
This model is fitted with dUIII control Cllr·
buretors type 5.S.1. (right and left).
Every 10000 kms. (6000 miles), the
carbure t or bowls should be cleaned oul tho-
roughly and 1I11 urburetor ducts blown throu-
gh with compressed air. Air should also be
used to clean the jets as the use of wire or
needles might alter the sil:e of the jets, and so
upset
carburalion efficiency.
Choke
Throttle slide
Atomizer
Main jet
Pilot jet
Needle
Floater
100
265
120
55
. MI 4 111 notch from top
. 29 mm. (1.14")
14 grams (X ounce)
Idling screw open Yo turn
This adjustment must always be made on a
hot engine.
Screw
in or out the horizont al screw (A)
which is the idle adjusting screw to fichen or
weaken the mixture. Screw B on the top of
carburetor is the throttle valve adjusting
screw.
To
adjust , proceed as follows:
1. Ensure both idle adjusting screws are open
about 3/4 of a turn.
2. Using the twist gr ip, open the thrOllle to
about 1/4 throttle and start engine.
3. Adjust the
throttle cab l es to a position that
both cylinders are firing even and with
the same amount of exhaust pressure.
4.
Re le llse the twist grip and adjust the
5 --- --1 1
6 --- -/ ,
15 -----:-; .--- tt ll
7 ~ ; 1 ~
8 ~' 4
13 --i\l
11
t=:~
Fig . 14
® -- 18
1 9 ~
@-20
21
~ 17
~ 23
~ 24
"

Determining
correct size
of main jet
36
throttle valves, using the adjustment (B)
on top of the carburetor to the desired idle
speed lind at a position where both cylin_
ders IIrc firing evenly.
5. Adjust the idle screw (AI to obtain the
best mi)(ture. It is best to remove the
sparkplug wire on the opposite cylinder.
After resetting the idle screws, readjust
the throttle valves for the desired engine
speed, if necessary. If it is necessary to
close the air or idle screw completely, the
pilot jet is t oo small, and one having a
larger orifice should
be fitted. If it is ne·
cessary to open the idle screw considera·
bly
more than 3/4 of a turn, the pilot jet
is too large and one with a smaller orifice
should be fitted.
6. Recheck to ensure
both throttle valves are
synchronized to open at the SlIme time,
and lock the cable adjusters and throttle
valve stop bolts in position.
7. Precise adjustments are best obtaine;:!
when using an electric tachometer.
When
the mi)(lU re is tOO weak, change to a
larger jet. If tOO rich, a smaller size main
jet should be fitted.
To determine the correct size of the main
jet, proceed as follows:
1 . If on opening the throttle the engine is
slow in picking up speed and the machine
does not go faster
or decelerates and shows a
tendency to backf,re, and on opening the air
lever there is seme imp rovement, then the
mi)(lUre is too poor due to a tOO small main
jet. In such case change to the jet size which
will give the best performance.
2
If on opening the throttle a duller e)(haust
tone
is noticed and the engine ejects black
Stripping of
carburetor
(See fig . \4)
smoke, also if on slightly opening the ai r
lever this condition
accentU~lIes, then the mi lt·
ture is too rich and a smaller size jet should
be fitted.
Remove:
Clamp 2 and lockring L
Complete mixture chamber cOver 3.
Throttle slide spring 4, throttle slide 5
with taper needle 6.
Air screw with spring 7.
Pilot j et 8.
Bowl cap nut 9, float chamber securing
bolt 10, washers 11, float chamber 12,
main jet 13. jet block 14.
Carburetor body 15 and cable tensioning
group 16.
Float
chamber with floater 17, adaptor
cap nut 18, adaptor 19, filter 20, and
washers 21.
Plug 22 and floater 23 with needle 24.
--
Fig. 15
37