MOTO GUZZI 850 GT 1972 User manual

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RIDER'S HANDBOOK

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SEIMM
ESERCJZ10 INDUSTRIE MOTOMECCANICHE S.p.A
2.000{()o,00(! Interllmenle '/er$eto
MHuno
DJrezione e Stabilimenti: 22054 Mandella dellario (Co~
Telefoni: 71112 e /.2512 (8 linee urbane)
Telegrammi' SEIMM MANDELLOLAAIO
Tale>'.: J8095 SEIMM MOTO GUZZI
C,C,LA. Milano n' 722044 Como n' 117437 • C. C Posta!o Como n° 18/422£ • Pos!ziore Commercia Estero M 986753
1st EDITION
RIDER'S HANDBOOK

INTRODUCTION
2
This booklet is intended to provide owners
with the necessary information on operating
and maintaining their machines for maximum
efficiency.
The manual should be read very carefully
as most troubles and failures arising from
neglect or poor maintenance
will be avoided
if all the instructions herein contained are
strictly followed.
Don't forget that aU major overhaul jobs and
repairs are best carried out by officially
appointed Moto Guzzi dealers who have the
necessary
facilities to quickly and competen-
tly repair your Moto Guzzi.
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INDEX
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Running in .
Controls and accessories
Identification data .
Tool kit .
Main features . Engine
Transmission
Frame
Instruments and controls
Ignition key .
Starting button
Ignition switch keys
Steering
lock
Steering lock keys .
Light
switch and horn button
Clutch lever
Twist grip throttle control
Carburetor starter control
Gearshift lever .
Front brake
lever
Rear brake pedal
Side stand .
Riding instructions
Engine
starting .
Caution
Starting a hot engine
Getting under way and stopping of
machine
On the way.
Lubrication
and general maintenance chart
Servicing instructions .
Lubrication
of engine .
Oil pressure relief valve
Oil pressure gauge
Lubrication
of gear box.
Lubrication of rear wheel drive
Lubrication of front fork
and hydraulic dampers
Lubrication
of bevels
in the steering .
page 5
7
10
11
13
16
16
19
20
21
21
21
21
21
22
22
22
22
22
22
23
26
26
26
27
27
27
29
31
31
32
32
33
33
34
34
3

Lubrication of wheel bearings .
Lubrication of control cables .
Lubrication of rear fork bearings
Oil breather unit
Carburation
Carburetor .
Standard carburetor setting
Adjusting the carburation
Stripping of carburetor
Air filter
Cleaning operations
Filters and fuel lines
Fuel tank
Fuel taps
Silencers
Cylinder heads. piston
and valves
Valve gearing
Tappet clearance
Checking valve timing
Ignition
Distributor .
Spark plugs
Checking of ignition timing
Checking
of ignition advance
by stroboscope lamp
Adjustments
Generator belt
Clutch lever
Steering
Steering lock
Front brake lever
Rear brake pedal
Rear suspension units
Checking the gear operating
mechanism .
Removal of wheels
Front wheel
Rear
wheel.
Electrical equipment
Wiring diagram .
page 36
36
36
36
38
38
39
39
42
44
45
45
46
46
46
47
49
49
49
52
52
53
53
54
57
57
57
57
60
61
63
64
65
66
611
68
69
75

RUNNING IN
After the
first 500 kms.
(300 miles)
Every 500 kms.
(300 miles)
During the first 1600 kms. (1000 miles), a
new or overhauled machine ought
to be used
with some intelligence as the efficiency, per-
formance,
and life of the engine are largely
dependant
on how it is run in.
The engine should never be allowed to reach
a high number
of revolutions before it has
had a chance to warm up sufficiently. Never
ride the machine at the highest permissible
speeds
for each gear before the machine has
been well broken in.
Should the engine speed drop
off considera·
bly on an uphill grade, a lower gear should
be immediately engaged. In case of overheat-
ing,
it is best to stop and allow the engine
to cool down.
Under
no circumstances whatever should the
following speeds
be exceeded in the running
in period.
Maximum permissible speeds:
Distance: up to 800 kms. (500 miles):
in low gear. 45 kms. (28 miles)
in second gear
65 kms. (40 miles)
in third gear
85 kms. (53 miles)
in fourth gear
100 kms. (62 miles)
in top gear
115 kms. (72 miles)
from 800 to 1600 kms. (500 to 1000 miles):
in low gear. 55 kms. (34.5 miles)
in second gear .
80 kms. (50 miles)
in third gear. . 105 kms. (65 miles)
in fourth gear .
120 kms (75 miles)
in top gear
.. 140 kms. (87,5 miles)
From
1600 to 3000 kms. (1000 to 1800 miles)
the speed
can be gradually increased up to
the maximum permissible limits.
Change the engine oil.
Tighten all nuts
and bolts.
Check valve clearance.
Check
distributor points.
Chek oil level. Correct level is in between
the minimum and maximum mark
on the
filler cap dipstick.
5

1
./1
Fig. 1

CONTROLS AND ACCESSORIES
(See fig. 1)
1. Front brake lever
2.
Air control lever
3. Throttle control grip
4. Starter button
5. Filler cap
6. Gearshift lever
7.
Pillion footrest
8. Pillion handgrip
9. Headlight
10. Speedometer
11. Ignition key
12. Rev-counter
13. Clutch lever
14. Light switch and horn
15. Side stand
16. Rear brake pedal
17.
Footrests
18. Center stand
19. Tail light
button
The machine can also be supplied with gear-
shift lever on the left and rear brake pedal
on the right.
N.B .. The tElrms -right. and .Ieft. in the text are used
in the Sense they would appear to One sitting in the
saddle.
7

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9

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Identification
data
(See fig. 4)
10
Every machine is identified with a serial
number which is stamped on the frame down
and on the
left hand side of the crankcase
cover .
This
number appears in the conformity certi-
ficate and is the only one valid to all legal
effects for the identification of the machine
- ... -~-
Fig_ 4

Tool kit
[See fig. 5)
',0
0
10 Wrench, box 19/21/22 mm
11 Wrench, open ended 17/19 mm
12 -Wrench, open ended 13/14 mm
13 Wrench, open ended 10/11 mm
14 -Wrench, open ended 7/8 mm
15 -Wrench, open ended, tappet adjusting
16 - Allen key, 5 hex
17 Pliers, universal
18 - Screwdriver
19 -Wrench, ring. double 22/27 mm
20 -Feeler gauge
21 - Screwdriver
22 Wrench. damper adjusting
23 -Tool bag
24 Instruction booklet
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1
Fig, 5
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11

Spare parts
Warranty
12
In case of replacements make always sure
that genuine MOTO GUZZI parts are used.
Failure
to do this will imply the loss of the
right to claim warranty.
The warranty period shall extend over a
period
of six months or 10.000 kms., which-
ever OCcurs first, from the date of purchase
and shall be limited to the free replacement
of a new part in exchange of the part which
may have proved defective.

MAIN FEATURES
ENGINE
(See fig. 5/ 1) CYcle
Number
of cYlinders
Cylinder
dispOSition
Bore
StrOke
DiSPlacement
Fig. 5/ 1
4 strOkes
2
« V» 90"
83 mm (3 . 26")
78 mm (3. 07")
844.05 cc. (51 .5 Cu .in.)
13

Valve gear
14
Compression ratio : 9.2 to 1
Revs at maximum
engine speed
6500 r.p.m.
Output at maxi·
mum engine speed: 64 HP SAE
Crankcase
Cylinders
Cylinder heads
Crankshaft
Crankshaft
supports
Connecting rods
Pistons
in light alloy
in Ugh alloy with hard
chromed barrels
in
light alloy, hemisphe-
rical.
with special cast
iron inserted seats
steel construction
in anti·friction material
pressed in 2 suitable
housings
steel construction
with
AL-TIN alloy thin wall
bearings
in
light alloy
O.H.V., push rod operated via the camshaft
in the crankcase
and gear driven by the
crankshaft.
Inlet:
-opens
24" before TOC
-closes 58" after BOC
Exhaust:
-opens 58" before BOC
-closes 22" after TOC
Rocker clearance for valve timing:
0,5 mm. (.0196")
Normal rocker clearance (cold engine):
inlet 0,15 mm. (.0059")
-exhaust 0,25 mm. (.0098")

Carburation
Lubrication
Cooling
Ignition
2 Dell'Orto carburetors type VHB 29 CD
(right) and VHB 29 CS (left), both gravity
fed from the tank.
Standard carburetor setting
-Choke 29 mm.
-
Throttle slide 60
- Atomizer 265
- Main jet 145
-Pilot
jet 45
- Starter atomizer: 80
With needle SV5 second notch from top:
idling screw open 1112 to 2 turns for the
left carburetor and 2 - 2112 turns for the
right carburetor.
Air intake provided with dry filter.
Pressure, by gear pump driven by the crank-
shaft.
Oil strainer in crankcase.
Normal lubrication pressure 3.8 - 4.2 kgs/sq.
cm. (54 to 60 Ihs sq.in.) controlled by relief-
valve.
Electrically controlled oil pressure gauge.
By air.
Cylinder and cylinder head deeply
finned.
By battery with automatic advance distri-
butor.
Initial advance: 5U•
Automatic advance: 28
u•
Ignition timing 33° full advance.
Contact breaker gap: 0.42-0.48 mm. (.016" -
.018").
Spark
plug: n. 225 in Bosch-Marelli scale or
equivalent (long thread 0 14 x 1,25)
Plugs point gap: 0.6 mm. (0.23").
Ignition coil.
15

Starting
Exhaust system
TRANSMISSION
Clutch
Gear box
Secondary
drive
FRAME
Suspension
Electric starter with electromagnetic ratchet
control.
Ring gear bolted
on flywheel. Operated by
starter button on the right handlebar.
Dual exhaust pipes and mufflers.
Twin driven plates. dry type. flywheel driven.
Controlled by lever
on the left handlebar.
Five speeds. frontal engagement. Helical
constant mesh gears. Cush drive incorpo-
rated.
Separate case bolted
on crankcase. operated
by rocker pedal
kom the R/H or L/H side
of the machine.
Engine gear-box ratios: to
1.235
{17-21l
Internal gear ratios:
low gear to 2 (
14-28)
second gear
to 1.388 {18-25l
- third gear to
1.047 {21-22l
-fourth gear to 0.869 {23-20l
-high gear
to 0.750
(24-18)
By constant speed double jOint cardan shaft.
Layshaft -bevel gear ratio: 1 to
4.625 (8-37)
Overall gear ratios:
- low gear
second gear
third gear
fourth gear
-high gear
Duplex cradle. tubular structure.
to
11.424
to 7.929
to 5.980
to 4.964
to 4.284
Telescopic front fork incorporating hydraulic
dampers.
Rear swinging fork
with externally adjustable
springs.

Wheels
Tires
Tire pressure
Brakes
Overall
dimensions
and weight
Performances
WM 3/2,15 x 18".
4.00 x 18 front and rear, block type (Super-
sport) .
Front
tire:
solo
with passenger
1.5 kgs/sq.cm.
21 p.s.i.
Rear
tire:
solo
with passenger
1.8 kgs/sq.cm. = 25 p.s.i.
2.0 kgs/sq.cm. = 28 p.s.i.
N.B .• The above recommendation is for normal riding
(cruising speed). If using the machine at constant high
speed or on motorways, the above pressure should be
increased by 0.2 kgs/sq.cm. (2.8 p.s.i.).
Expanding type. 220 mm. dia. (8.66").
Twin leading shoes front brake operated by
hand
lever on the right handlebar.
Large rear brake operated on left hand side
of machine.
Wheelbase 1.470
mts.
(about 57.8"
Length 2.245 mts.
(about 88.3"
Width
0.795 mts. (about 31.3"
Height
(dry)
1.050 mts. (about 41.3"
Minimum ground
clearance 0.150 mts. (about 5.9"
Curb weight 249 kgs. (about 548Ibs.)
Maximum permissible speeds in each gear,
solo riding:
- bottom gear 68 kms/h (42 m.p.h.)
climbability: 86%
-second gear 98 kms/h 61 m.p.h.)
climbability: 46%
- third gear 131 kms/h (82 m.p.h.)
climbability: 28%
17

- fourth gear 164 kms/h (102 m.p.h.J
climbability: 17%
high gear 193 kms/h (120 m.p.h.)
climbability: 8,9%
fuel consumption:
6.5 I. x 100 kms (CUNA)
Fuel and oil capacites
Group or part
Fuel tank
Reserve
Sump
Transmission
Rear drive box
(bevel set
lubrication)
Front fork dampers
(each leg)
18
Quantity
22.5 liters
liters
3 liters
0.750 liters
0.230 liters
0.160 liters
Recommendation
Petrol 98/100 NO R.M.
Shell Super 100 multi-
grade or equivalent
Shell Spirax H.D. 90
Shell Spirax H.D. 90
Shell Tellus 33