MOTO GUZZI 850 Le Mans III Instruction manual

~) [LeMans]
(.mrH)
ORISHOP MANUAL
COD. 28920151
Add iti ons to the Workshop manual for the models V1000 G5 and 1000 SP -Code 17920161

Til. lIIu llrlUOfII Ind clescripliOfl. In 11111 booklel I .. Indlcall •• 0fI1y .nd Ih . manullcturlr r ........
itMlf the righl 10 Introduce . ny modiliceilon It !MY <$e.m n.c .... ry I",. bell .. ptrformllnce ",. lor
"""stRlctJy.",. COftIm.rclel ... son, wlthoul prior notice.
SEIMM MOTO GUZZI - TECHNICAL PUBLICATIONS
CODE 28 92 01 51
2001< · 7·B7 · Prln!ed In Italy· UlopressIBe'lIlmo

~ ________________________________________ ______ ________ ~ 228
HINTS ON THE PROPER USE OF THIS MOTORCYCLE
Due to itsexceptionally high feature, this motor-
cycle can be considered as in the racing ma-
chine class and as such has to be ridden In a
sportsmanlike way. For this very reason, it has
met the favour of many motorcycle fans but,
same as for all racing bikes, it has to be used ac-
cordingly.
For instance , for fuel f eed this model is fitted with
carburettors with pumps and if the twist grip is
not used correctly in accordance with the en-
gine revolutions, there might be an excess of
fuel which is ejected by the carbu rettors, ending
in the air filter box of the carburettors sam ,:! .
When travelling allow speed or in ather words at
low revs, it is nece ssary forthethrottle grip to be
used with care since the immission of a greater
quantity of fuel might
not be fully absorbed by
the engine.
At high speed, also in case of abrupt accelera-
tions, the fuel is entirely absorbed and used up
by theengine,thus eliminatingthisrisk and con-
ferring to this model the brilliant .. kicking up ,.
qualities that make it one of its outstanding fea-
tures.
175

INDEX
Cylinders
Pistons
Con-rods
Crankshaft
Carburettors
Float levelling
Replacing the air filter
Fr ont fork l ubrication
AND all! CIIINGI
Oi l pneumatic shock absorbers
,. • T • ..
• ,~ I "'
25 " ' ,
. '~ ... ' .'-.' ....
page 179
_180

MAIN FEATURES
ENGINE
- cy linder di sposition
- bore
-st roke
-displacement
-compression ratio
-max torque
VAL VE GEARING
CARBURATION
LUBRICAnON
GENERATOR ALTERNATOR
IGNITION
-ignition data
- con ta ct br eaker pOints gap
- spa rk plugs
-plug poin ts gap
- ig nition coils
STARnNG
TRANSMISSIONS
CLUTCH
PRIMARY DRI VE
GEARBOX
- gear ratios:
L ow gear
2nd gear
3rd gear
4th gear
5th gear
SECONDARY DRIVE
-ratio
-overall gear ratios
(engine-wheel)
L ow gear
2nd gear
3rd gear
4th gear
5th gear
twin cy linder - 4-stroke
.v .. 90 o
83 mm
78 mm
844 cc
9.8 10 1
7.6 kgm at 6200 rpm
O.H.V ., push rod operated
n. 2 carburettors _Dell'Orto. type
PHF 36 B (0) (righ t)
PHF 36 B (5) (left)
pressure, by gear pump
wire gauze a nd cartridge filters in oil sump
normal lubrica ti on pressure 3.8 to 4.2 kg/sq em
(pressure relief control valve in the sump)
oil pressure sender unit in the cra nk case
fitted in the front part of the cra
nk shaft (14V - 20A)
cOil-battery ignition with double contact br eaker
a
nd automatic advance with centrifugal masses
ignition advance (fixed) 80
automatic advance 260
full advance (f. + a.) 34
0
0. 37 ...... 0.43 mm
Bosch W 5 0
Lodge 2 HLNY
0.6 mm
n. 2 fitted on the frame
el ectric starter (12 V - 0.7 KW) with electromagnetic
ratchet control ring gear bolted on the flywheel
starter button (STA RT) fitted on the R/H side of handlebar
twin driven plates, dry type
fitted on the flywheel side
hand controlled
by lever on left handlebar
by gear s, ratio 1 to 1. 235 (Z = 17/21)
5 speeds, frontal engagemen t, constant mesh gears.
Cush
dr i ve incorporated
pedal operated on the UH side of the bike
1102 ( Z ~ 14 / 28)
1 to 1.388 (Z ~ 18/25)
1101 .047 (Z-2 1/22)
1 10 0.869 (Z ~ 23/20)
1 100 .750 (Z ~ 28/21)
by cardan shaft, bevel gear set
11 04 . 714(Z~7 / 33)
1 to 11.643
1 10 8. 080
1 to 6.095
1 10 5.059
1 10 4.366
177

FRAME
SUSPENSIONS
-front
-rear
WHEELS
-front
-rear
TIRES
-front
-rear
BRAKES
-front
-rear
DIMENSIONS AND WEIGHTS
-wheel base (loaded)
-max length
- max width
-max
height
-min. ground clearance
- dry weight abt
PERFORMANCES
- top speed
-fuel
consumption
FUEL AND OIL CAPACITIES
duplex cradle , tubular structure
telescopic fork .. MOTO GUZZI patent ..
with oil pneumatic shock absorbers
swinging fork and rear dampers with adjustable ex ternal
springs
co n ce ntric to the oil pneumatic shock absorbers
light alloy castings with rims:
WM 3/2.15 x 18" CP2
WM 3/2.15 x 18" C P2
100 /90 V 18
110 /90 V 18
disc type with caliper having 2 cy linders , controlled
by hand lever on the R/H side of the handlebar
hydraulic transmiss ion independent from the rear brake:
disc dia. 300 mm
braking cylinder dia. 38 mm
master cylinder dia 12 .7 rnm
disc type with fixed caliper with two cy linder s
fool controlled with pedal on the R/H side of the
bike :
di sc dia . 242 mm
braking
cy linder dia . 38 mm
master
cylinder dia. 15.875 mm
the rear brake
is co nnected by an hydraulic
transmission to a second brake on the front wheel
having the same features
and size as the hand
con trolled front brake
1.505 m
2. 190 m
0.640 m
1.160 m
0. 175 m
206 kg
230 km/h (144 mph), solo
5.7 I x 100 km
-fuel tank 25 I
(6 .15 US g[s) supergrade petrol (971100 NO ·RM)
(reserve 3 [ about) (3.1/4 quarts)
-oil s
ump 3 [ (3.1/4 quarts) oil « Agip S[NT 2000 SAE 10 W/40 "
-gear box 0. 750 I (1.3/4 pints) oil .. Agip Rotra MP SA E 90 ..
-rear drive box
(bevel gear set lubrication)
-front fork (each leg)
-braking
circuits
(front and rear)
178
0.250 I (9 oz abt) oil of which : 0.230 t (8. 114 oz abt )
«Ag ip F. 1 Rotra MP SAE 90 " and 0.020 I (3/ 4 oz)
«Agip R oco l ASO/R» or Molikote .. A" type
0. 060 I (2 oz abt) ftuid .. Agip ATF Dexron»
fluid "Agip Brake fluid - Super HD "

II SERVICE SCHEDULE
IT EMS
MILEAGE 900 ml. 1800 ml.
3700 mi.
COVERED ~ 1500 km 3000 km 6000 km
•
•Engine oil R R R
•
on filler cartri dg e R
• Wire gauze oil filler C
•Air IiIter C
• Ignition timi
ng A A A
•Spark plugs A A A
• Rocker clearance A A A
•
Ca rburelion A A A
•Nuts and bolts A
•
Fu el lonk , fitters a nd pipes
Gear box oil A A A
Rear drive box all A A A
Wheel and steering bear ings
Fork legs oil
Starter motor and generator
Brake syste ms fluid A A A
Brake pads A A A
... _ l n~C l lonl _ Adjust ... .., •• • Po ul ble '.pl • .,. .... " .. . Servicing I C _ CIe..,lng. ' ft _ Rapt_mlnt a.
• O per a tion r equ lr. " 101 m . l n~ln"" t ... ... hlel. "« 0 .0:1 1 "'1110 I ml ul"" .. 'u l. II ..... (U S ,, ).
5600 ml. 7500 mi.
9000 km 12 ,000 km
R R
R
A A
R A
A A
A A
C
R A
R A
A A
A A
O ecu t on ally, chic k Iha ellcl rolyte Ie •• l ln bl n. 'Y. , .. b,'ute lol n tl I " d .,.bl .. : •• • ., 500 k," (300 ", II •• ) c~ .e k t toe .n,ln. 0" 1• • • 1.
In .n , c .... '. n .... tll il oll. t 1 ... 1 one • • , eo ,.
9400 ml. 11,300 ml.
13 , 200 mi. 15 ,100 mi. 17,000 ml. 18, 900 ml.
15,000 km
18 ,000 km 21.000 km 24 ,000 km 27 .000 km 30,000 km
R R R R R R
R R
C C
C R R
A A A A A A
A R A A R A
A A A A A A
A A A A A A
A A
C C
A R A A R A
A R A A R A
A
R
A
R A A A A R
A A A A A A

ENGINE OVERHAULING ANO CHECKING
229 L- ____________________________________________________ ~
180

CYLINDERS
SELECTION OF CYLINDER DIAMETER
GRADING A GRADING B
GR ADING C
83 . 000 +- 83 . 006 rnm
83.006 +- 83 .012 mm 83.012
+83 . 01 8 mm
3.2677 +3.2679" 3.2679 + 3.2681" 3.26
81 + 3.2684"
PISTONS
SELECTION OF PISTON DIAMETER
GRA DING A GRADING B GRADING C
82.968 + 82 .974 mm 82. 974 +- 82. 980 mm
82 .980+- 82 .986 mm
3.2664 + 3.2666" 3.2666 + 3.2669" 3.2669 + 3.2671 "
The pistons of an en gi ne must be balan ce d; a
weight difference between them of 1.5 gr Is al-
lowed.
N.B. - Th e above selection values are valid for
the model 850 La Mans
II starting from
engine n. 80390.
When fi tting a piston check that the class mark
stamped on the piston and the word .. SeA.
(exhaust) are facing the exhaust ho le in the cy -
ti nder.
4.02 + 4.04
3.990+ 3.978
0 "
0.30 + 0. 45
1.52 + 1.54 r:"'===: = I E~~ffi o =
21.994 + 21 . 198 59.984 +59.910
o 22.000+22.006
Values In mm
1. 490 -0- 1.47'
1. 490 + 1. 418
L- ________ __ ____________ __ ______ ____ __________ ________ ~ 2~
181

CON·RODS
2102S +22. G45
1 39.975 +1 40 .02.5
Mil patlilelis. Ind ".,linln..,
di Herence .elwlln bDtb uis lAeuurd
I' I di rtlnee ., 200 mm ± 0.10
,--=,-' 00 _r'\\
4.6 -t- U Kim
Values in mm
231 L- ___________ ----'
CRANKSHAFT
Crankpin diameter:
STANDAAO PRODUCTION PI N
44.008 ~ 44.020 mm
1. 7326 ~ 1.7331"
0.25 4 mm I .010'
43.754 --r- 43. 766 mm
1.7225 ~ 1.7230"
Mainshatt diameter, timing side:
STANDARD PRODUCnO N PIN
0.2 mm I .007S"
37.975 ~ 37.959 mm 37 .775 ...... 37.759 mm
1.4951 ~ 1.4944" 1.4872 ~ 1.4866"
182
23.800 + 23 . 850 23.800 -:- 23.600
~
~
25.064 + 25.097
N
,.
~
-
rf; 22.020 ...... ZZ . a41
:;
N
AFTER PftESSING IN COD.ftOD
BRING IT TO A OrA. OF
22 . 025 ...... 22 . 045
I~DT AL THICKNESS
I STEEl ..... AH TIF R. II.535 ..... 1.544
~ ~
M
• In
r-
a
.,.
U
0
~
-
"
•
Z3 . 800 -t- 23 . 850
CUSSES
ClASS •A· CtASS •B.
BLUE DOT
WHITE DOT
ON STEM ON STEM
41.130 + 41.136 47.13S ..... 47 .m
Values in mm
232
U NDERSIZEO
0'
0.508 mm I .020' 0.762 mm I . 030'
43. 500 +- 43. 512 mm 43.246 ....... 43.258 mm
1.7120 ~ 1.7130" 1.7025 ~ 1.7030"
UNDERSIZED
0'
0.4 mm I .01574" 0.6 mm I .02362"
37.575 ~ 37.559 mm 37. 375 ~ 37.359 mm
1.4793 ~ 1.4787"
1.4715 "'" 1. 470r

Mainshaft diameter, drive side'
STANDARD PR()()I.X;nON PIN
0.2 mm I .0078"
53 .970 "'" 53 . 951 mm
53.770 ~ 53. 751 mm
2.1248 ~ 2.1240" 2.1169 ~ 2 . 11 62 "
CHECKING CRANKSHAFT BALANCING
To balance statically the crankshaft it is neces-
sary to add a weight of 1.650
..... 1.652 kg.
SHIM ClEAIWICE
Values In mm
UNDERSIZED OF
0.• mm I . 0157." 0.6 mm I .02362"
53 .570 "'" 53 . 551 mm
53. 370 ~ 53.351 mm
2.1090 + 2.1083" 2.10
11 ~ 2.1004"
L- ________________________________________________ ~ 233
183

18 ,5
17 ,5
235 ~ ________________________ ~
184
CARBURATION
CARBURETTORS
N. 2 Oelt'Orto type car burettors .. PHF 36 B (0) ..
(right) • PHF 36 B (S). (left)
Controls
• throttle control grip on the R/H si de of the
handlebar;
• easy starter lever for
co ld engine starts on the
UH side of crankcase.
.. A ,. starting position for cold engine.
.. 8" riding po sition,
Standard
carburettor settings:
Choke ¢ 36 mm
Throttle valve
60 /3
Atomizer 268 A 8
Main
jet 115
Idling jet 50
Sta rter jet 70
Pump jet 33
Needle K 18 (3 '~ notc h)
Float 10 gr
Idling sc rew adjustm en t: opens 1 1/2 turns
FLOAT LEVELLING
To level the floats place the carburettor in verti-
cal position as sh ow n In fig. 235.
N.
B. -Contrary to what said in the wo rk s hop
manual code 14 92 01 56 the above values are
valid al so for model 850 Le Mans I I.

,\
185

237
REPlACING THE AIR FILTER
Every 6000 km (3700 miles) check condi tions of
airfiller, if necessaryclean it using
co mpressed
ai r; it is advisable to replace it every 9000 km
(5600 miles).
To replace the air filter lift the saddle, remove
fuel t ank and side covers. Take ou t R/H car bu-
rettor and undo the sc rewsfixing the air intake to
the bike frame: remove the two side
sc rews and
take out from the R/H side the container .. A.
complete with the air filter.
n8 ~ ____ ~ ______________________________________________ ~
186

SUSPENSIONS
FRONT FORK LUBRICATION
To replace the oil in the front fork legs, proceed
as follows:
• with the bike on the central stand, loosen the
side screw .. C .. locking the steering head to the
fork arm; disconnect compensating pipe and
completely unscrew the hexagonal screw plug
« 8» ; then undo drain plug "A .. ;
• slightly press the front part of the bike to
force out the plug «8 » which is solidal to the
shock absorber. Do this paying attention not to
damage the instruments panel;
• refit plug .. A ,. and introduce the quantity of
fluid necessary (60 cc Agip F. 1 ATF Dexron)
through the space existing between the
inner
diameter of the fork and the shock absorber
body ;
• release the front part of the bike refit plug
... B» and lock the side screw. Repeat the same
operation for the other fork leg;
• reconnect compensating pipe and check
the pressures keeping to the given values.
OIL PNEUMATIC SHOCK ABSORBERS
The operating load pressures of these shock
absorbers are the following;
• front: 2 ..... 3 kg/sqcm
• rear: 3 ..... 5 kg/sqcm
To check the pressure it is advisable to use a
pressure gauge having a very short pipe (better
ifany), asthe capacity of the pipe mayaffect the
pressure existing inside the shock absorbers.
To ascertain to whic h extent your pressure
gauge reduces, when taking the measurement,
the pressure inside the sho ck absorber it is suf-
ficient to carry out two consecutive measure-
ments:the difference between the two readings
gives approximately the pressure reduction oc-
curing whenever a measurement is taken.
Th e measurement must be taken with the bike
on the central stand and with cold sho ck ab-
sorbers; to charge the shock absorbers only
use moistureless air.
N.B. -Pressures gauges as above, are found on
the market:however
it can be necessaryto place
a supplementarygasket in the gauge head, in or-
der that the valve steminside the shock absorber
will be pressed only when the gaskethas madea
perfect tightening.
239
Be fore modlficatlon
i'M Odificauon
L- ________________________ ~ 240
187

241 ~ _________ -.J
188
.[
~
,
,
~
+
L- ________________________ ~ 242

ED SWINGING FORK
'P-' 1';,:;
~
II-
.1---
/.. I
'"
, -
, ~
;
"'.000 ·· 136.100 I
"I .
,
-I-
;
KITS SUPPLIED ON REQUEST
The following kits remain valid:
• GEARBOX SET OF ST RA IGHT TOOTHED
GEARS
foreseen in the workshop for the model 850 Le
Mans
II -code 149201 56 .
~
I-
"'mm
1 40 .5 m"
mm
i§
-r
) m"
61 .991 + 61 .
mm \
1\
-,
"-
II
18 . 1 50 + ~~ ~m
. ", :m 243
189

190
ELECTRICAL WIRING DIAGRAM
1 Pa rking ligh t. !r ont (4 WI
2 Hig ht beam bulb (45 Wj
3 low beam bulb (40 W)
4 3~way connector for headlight (AMP)
5 4. way connector Molex
6 IS - way connector
7 12-way con nector
8 Ignitlon key (3 positions)
9 Voltmeter (3 W)
10 Tachometer (3 W)
11 Rev -co unter (3 W)
12 Warning lig ht , right t ur n signal ( 1. 2 WI
15 Warning light. parking (1.2 W)
16 Warning li ghl high beam (1 .2 W)
17 Warning Ugh t, brake fluid level (12 W)
18 Warning light 011 pressure (1.2 W)
19 Warning light, generator (1.2 W)
20 Werning light, neutral posiUon (1 .2 W)
21 Warning light, le ft turn signal (1.2 W)
22 Switch lor sim ul tane ous turning on of all flashers
23 Turn flasher, !ront, r
ig ht (2 1 W)
24 Turn flasner, Iront , lett (21 W)
25 Turn flas her , rear, rig ht (21 W)
26 Turn flasher, re ar , left (21 W)
27 Engine starting and st op button
28 Flashing light turn signals, and horn switch
29 Horn
30 Front brake switch (STOP)
31 Rear brake switch (STOP)
32 Flashing li ght relay (FLASH)
33 Rectiller
35 Alternator (1 4 V - 20 A 21)
35 Regulator
36 Battery
37 S la rter motor relay
38 Starter mot or
39 Terminal block with fuses (16 A)
40 Taillig ht
41 Rear sl op light (2 1 W)
42 Number plale and rear parking light (5 W)
43 3-way connector
44 Flasher box
45 Oil brake level solenoid
46 Neutral position solenoid
47 Oil pressure solenoid
48 Coils
49 Spark plugs
50 Cont ac t breaker

IGNITION SWITCH POSITION
Posit I :
NO contac ts
PosU. 2:
Con l acts on all lermlnals
Posit. 3: Contacts on terminals 16130
PO$., POS.2 f'OS. 3
•
BI _ White
N _ Blac k
G _ Yellow
V _ G.aen
R _ Red
B _ Blue
VI _ VIOlet
RO _ Plflk
A _ Orange
M _ Brown
Bl . N _ White·Btack
GR _ Gray
AI _ U gh l blue
B-N _ Blue· Black
V-N _ Green- Blac k
R-N _ Red-B leck
AZ-N _
Ught blue- Black
R-B
I
tp®
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Jfi • I =
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( 1
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" 'CAS'
"""N
RO
R
TURN
,
@
c;.,
@\V
c;.,
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@ @
N = r r
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=
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IGNITION SWITCH POSITION
Posil I ' NO contacts
Posit 2: Contacts on all lermlnall
Posit. 3: Conl acts on terminals 16130
POSt FOS2 FOS3
" _ White
N _ Black
G _
Ye llow
V _ Green
R _ Red
B _ Blue
VI
_ Violet
RO
_ Pink
A _ Orange
" _ Brown
BI.N _ White-Black
GR
_ Grey
AI
_ U gh l blue
B~N
_ Blue-Black
V~N
_ Green-Black
R~N
_ Aed-Black
AI~N _ Ught blue-Black
.. ~
I
@
"
R
R_R
/.
,
R
RO