MOTO GUZZI Le Mans 850 Instruction manual

14 920151
[~L741 ]
~ ,I,eMans J
ADDITIONS AND CHANGES TO THE WORKSHOP
MANUAL FOR V 7 SPORT· 750 S . 850 T

MAIN FEATURES
Engine
Cylinder disposition
Bore
Stroke
Displacement
Compression ratio
Output
VALVE GEAR
2-cyllnder, 4-stroke
.. v .. 90'
mm 83
mm 78
cc 844
10,2
HP 80 SAE at 7300 rpm
D.H.V. push rod operated.
CARBURETION
2 Dell'Orto Carburettors type PHF 368 (0) rIght
PHF 368 (S) left.
LUBRICATION
Pressure, by gear pump.
Normal lubrication pressure, 3,8 -:- 4 ,2 Kp/crn2
(controlied by relief valve),
Wire gauze and cartridge oil filters.
Electrically controlled oil pressure gauge.
GENERATOR
(14 V - 20 A) Front on the crankshaft.
IGNITION
By battery, with double contact breaker and au-
tomatic advance.
Ignition data:
Initial advance (fixed) 8"
Automatic advance 26"
Full advance 34'
Contact breaker point gap mm 0,37 -:- 0,43
n. 2 spark plugs
n.2 ignition coils, on the left side of frame.
STARTING
Electric starter with electromagnetic ratchet
control. Ring gear bolted on flywheel.
Starter button (START) right on the handlebar.
TRANSMISSION
Clutch: Dry type. multiplates. Lever controlled
from the L/ H side of the handlebar.
Primary drive: via the gearbox
ratio: 1 : 1,235 (Z =
17 / 21) .
Gearbox: Five speeds. Frontal engagement. con-
stant mesh gears Cush drive incorporated. Pe-
dal controlled from the L/ H side of the motor-
cycle.
Ratio:
low gear 1: 2
2nd gear 1 :3,
388
3rd gear 1 : 1, 047
4th gear 1: 0,869
5th gear 1: 0, 750
(2 = 14 / 28)
(2 = 18 / 25)
(2 = 21 / 22)
(2 = 23 / 20)
(2 = 28 / 21)
Secondary Drive: cardan shaft (bevel gear set)
ratio: 1 : 4.714 (Z = 7/
33)
Overall gear ratio (engine/wheel)
low gear 1
:11,643
2nd gear 1: 8, 080
3rd gear 1 : 6, 095
4th gear 1: 5,059
top gear 1 : 4,366
CYCLE
Frame: Duplex cradle, tubular structure.
Suspension: Telescopic front fork incorporat-
ing sealed hydraulic dampers.
Rear swinging
fork with externally adjustable
springs.
Wheels: in light alloy with rims
WM 3/2,15 -18" front and rear.
Tyres:
Front 3, 50 H - 18" or 100/90 H - 18"
Rear 4,00 H - 18" or 110/90 H - 1S"
or 4, 10V-1S"
Brak.s:
Front: Hydraul ic disc brake, twin braking cylin-
der caliper. Hand lever controlled from the R/ H
side of the handlebar. Hydraulic transmission
free from rear braking system.
Disc
0300 mm
Braking cyl. 0 38 mm
Master cyl. 0 12 ,7 mm
Rear: Hydraulic disc brake, twin braking cylinder
caliper . Pedal lever controlled from the R/ H side
of the motorcycle .
Disc 0242 mm
Braking cyl. 0 38
mm
Master cyl. 0 15,875 mm
The rear brake is bound by a hydraulic transmis-
sion to a twin front brake featured and dimen-
sioned like the hand controlled one.
Dimension. and weights
Wheelbase (under load)
Max. length
Max. width
Max. height
Min. ground clearance
Ory weight
PERFORMANCES
m 1,470
m 2,190
m 0,720
m 1,030
m 0, 150
kg 198
Max. speed, solo
Fuel consumption
210 km/ h
It 8x 100 km
173

FUEL AND OIL CAPAcmES
GROUP OR PART QUANTITIES RECOMMENDATION
Fuel Tank It
22 ,5 Petrol
98 / 100 NO·RM
(Reserve 3 It)
Sump I, 3
Agip SINT 2000 SAE 10 W/ SO
Gearbox "0,750 Agip F. 1 Rotra MP SAE 90
Rear drive box 1"0,230 Agip F. 1 Rotra MP SAE 90
(bevel set lubrication) "0,020 Agip Roeol ASO/ R
Front fork (p. leg) "0,120 Agip F. , Dexron
Front and rear brakes
Ag ip F. l Brake Fluid SAE -J 1703
174

ENGINE INSPECTION AND OVERHAULING
CylInder hAd cowef"l .. Cylinder head••
V.Iv .... SprInge .. Valv. guldel
To take the valve guides off the cylinder heads
use the proper punch (see fig. 22). The valve gui-
des are to be replaced when the clearance bet-
ween v al ve and valve guide is not avoided by
replacing the valves only.
To press the valve guides onto the cylinder
heads use the
proper punch (see fig. 23). Heat
first the cylinder heads and lubricate the valve
guides. The valve guides pressed, ream properly
the in
ner bores (where the valve stems slide)
using a
proper tool in such a way to br ing the
inner
13 at the exact measure and data which
are given in the table hereunder (see Drwg. fig.
348). The negative clearance between valve gui-
des and cylinder heads must be within mm
0,046 ..;- 0,075.
COUPLING DATA BETWEEN VALVE AND VALVE GUIDES (see Drwg. fig. 348)
VALVE GUIOE INNER"
VALVE STEM" ASS EMBLING CLEARANCE
Inlet 8,000
..;- 8,022 7,972
..;- 7,987 0,013 -+- o, osa
Outlet 7,965
..;- 7,980 0.020
"' 0.057
Vatve .. ats
The valve seats have to be reground with a
proper grinder to provide a good coupling
with valves. The valve
sea.t · inclination angle is
45'30' ± 5.
Vatv" (see Drwg. fig. 348)
Ensure the clearance between valve stem and
valve guide is within the right limits. The incli-
nation angle of the valve plate is 4S"3O' ± 5. The
plate 0 of inlet valve is 44 mm while the plate 0
of outlet valve is 37,000 -+- 37,100 mm.
175

CYLINDERS • PISTONS • PISTON RINGS
Cyllnde... (see Drwg. fIg. 349)
IntpeCtton
Measure the cylinder bore at the top, middle and
CYLINDER '"
bottom on both transversal and longitudinal di-
rections. In case off limits of values re-bore the
cylinder considering that pistons and piston
rings are available with the following oversizes:
4/ 10 and 6/ 10.
STANDARD VALUE 4/ 10 oversize
6/10 oversize
83,000 -;- 83,018 83.400
-:- 83,418 83,600
-:- 83,618
SELECTION OF CYLINDER '"
CLASS -A_ CLASS .e.
83,000 -+- 83,009 83,009
-;- 63,018
Note: Class ",A .. cylinders must be matched with
class .. A,. pistons; the same for class «6" cy-
linders and pistons.
PI.tons (see. Drwgs. fig. 349-3 50)
At the time the engine is overhauled, clean the
PISTON '"
121 • P.
••
standard value 74.400 + 74.600
4/ 10 oversize 74.800 + 75.000
6 /10 oversize 75.000 + 75.200
PISTON '" SELECTION
CLASS .A. CLASS .s.
82,936 -;- 82,945 82.945 + 82,954
Note: Class "A .. piston must be matched With
class "A
.. cylinders; the same for class ,, 8 .. pi-
stons and cylinders.
Fitting of a piston onto a con-rod
Before fitting a piston on to a con-rod, it is ne-
cessary to heat it in oven in oil bath at about
60 'C; this will allow a li ght dilatation of piston
holes, thus making the introduction of the piston
pin easier.
COUPLING DATA BETWEEN PISTON PIN
AND PISTON HOLES (see Drwg. fig. 350)
PISTON RINGS
Each piston fits three types of pistons rings:
17.
piston crown and the piston ring slots of all
carbon deposits. Check then the clearance bet-
ween cylinders and pistons relating to 0 selec-
tion. If such clearance is over the table values,
it will be necessary to re-bore the cylinder consi-
dering that the piston is available with the follo-
wing oversize: 4/ 10 and 6/ 10.
Pistons must be balanced; a weight difference
of 1,5 gr is allowed. The selection measure must
be taken
at 22 mm from the piston bottom. (see
Drwg. fig. 349 and Selection Table).
When fitting a piston pay attention that both the
piston selection
mark and the wording ·SCA ..
(exhaust) face the cylinder exhaust hole.
121 d <l •
••
82.000 + 82.200
82.400 + 82.600
82,600 -;- 82.800
1 - Upper se.1 ring
standard 0
4/ 10 oversize
6/ 10 oversize
ring thickness
ring gap
slot clearance
" •a •
~
82,936 -;- 82,954
83,336
-;- 83,354
83.536 +
83 .554
mm 83 ,000
mm 83,400
mm 83,600
mm 1,490 + 1,478
mm 0,30 + 0,45
mm 0,30 + 0,62
2 - Middle seal ring, step 011 scraper
standard 0
4/ 10 oversize
6/ 10 oversize
ring thickness
ring gap
slot clearance
3 - 011 scraper ring
standard 0
4/ 10 oversize
6( 10 oversize
ring thickness
ring gap
slot clearance
mm 83,000
mm 83,400
mm 83,600
mm 1,490 + 1,478
mm 0,30 + 0,45
mm 0,30 + 0,062
mm 83,000
mm 83,400
mm 83,600
mm 3,900 + 3,878
mm 0,25 + 0,40
mm 0,042 + 0,060

CON-RODS = CRANKSHAFT
Con~roda (see Drwgs. fig.351·532) CON-ROD SELECTION
Loading torque for con-rod cap securing nuts:
4,6 -:- 4,8 kpm.
Allowed con-rod weight imbalance: gr 3.
CRANKSHAFT (s ee Orwg. fig. 353)
CRANKPIN "
STANDARD
VALue
0,254
44,008 + 44,020 43,754 + 43,766
CRANKSHAFT SELECTION
CLASS oA- C
I.ASS .8.
-B l ue. mark on the .White. mark on the
shoulder. flywheel shoulder flywheel
side side
44,008 + 44,014
44 ,015 -:- 44,020
CLASS ./4,.
CLASS · 8.
_Blue" mark .White_ mark
on the rod
on the rod
47 ,130 -:- 47 ,136 47.136
-:- 47,142
BEARING UNDERSIZES
0,508 0,762
43,500 ..;.. 43 ,512 43 ,246 -:- 43,258
Clearance between crankpln and bearing: Min.
0,030 Max. 0,054.
Inspecting the crankshaft balance
Static balancing of the crankshaft is obtained by
applying a weight of kg 1,
586 -:- 1.616 onto the
pin.
177

VALVE GEARING
nmlng dm
Timing data (referred to the clearance of 1,5 mm
between rocker and valve) are the following (see
fig, 260).
Inlet:
- opens 20' before T.O.C.
-closes 52' after B.D.C.
Outlet:
-opens
52" before B.D. C.
-closes 20' after T. O.C.
Working clearance on a cold engine: mm 0, 22.
o OF CAMSHAFT BEARING AND HOUSINGS IN CRANKCASE
CAMSHAFT SEARI NG
HOUSINQ IN CRANKCASE FITTI NG CLEARANCE
Valve gearing ~ide 47,000 -:- 46,984 47,025
-+- 47,050 0,025
-+- 0,066
Flywheel side 32,000
-:- 31 ,984 32,025 -;- 32,050
COUPLING DATA OF TAPPETS AND GUIDES ON CRANKCASE
11 0 OF GUIDE
Original 22,021 -;- 22,000
0,05 mm oversize 22,071
-;- 22.050
0,10 mm oversize 22,
121 .;- 22,100
FITTING OF CAMSHAFT ASS. Y,
After fitting the oil pump and the chain tensioner
proceed as follows:
-Fit the camshaft .. A .. fig. 261 into the crank·
case housings and secure it to the crankcase
using flange
.. 8 .. fig. 261 then lock the screws
with toothed washers
.. C .. fig. 261 .
-Fit the gears with mounted chain "D
,. fig. 261
onto: camshaft. crankshaft and oil pump control
shaft. paying attention to the alignment
of the
reference marks
.. E. fig. 261 indicating that the
engine is timed (valve gearing); then fit the stop
pin «F. fig.
261 into the holes of gear "G .. fig. 261
and camshaft «H .. ; pay attention also to the key
hollow on the engine pinion .. I,. lig. 261.
-
Lock the nut with toothed washer .. M .. fig. 261
securing the gear to the camshaft. using holdfast
tool n. 14927300 (20 fig. 262 ) and wrench
189276 SO ( 60 fig. 262) for the nut 27 or wrench
14927600 for the nut 26.
- Lock the ring with washer .. M,. fig. 261 secu·
ring engine pinion to the crankshaft. using hold-
fast tool 14927300 (fig. 263) and special wrench
189276 SO (60 fi g. 263) bend then one washer
wing into a ring hollow.
- Lock the nut with spring washer .. N. lig . 261
178
010 OF TAPPET
Fm l NG CLEARANCE
21 ,996 -:- 21 ,978 0,004 -;- 0,043
22.046 -:- 22,028 0,004
-;- 0,043
22,096 -:- 22, 078 0,004 -;- 0,043
securing the gear to the oil pump control shaft
(remember to fit the key
.. 0. fig. 261 onto the
shaft) using
holdlast tool 14927300 and special
eye wrench.
The
group fitted and nuts and ring locked. re-
member to check the proper alignment of the
reference marks on camwheel and engine pinion
.. A .. fig. 264 and to fit the tappets " Q.. fig. 261
into the giudes on crankcase .. p .. fig. 261 .
Checking the valve liming
wIth engIne Installed on vehicle
Proceed as follows:
- Re move the spark plugs.
-Remove the rocker box covers.
-Set a clearance
of 1,5 mm between rocker
and valve.
-Undo the screws and remove t he alternator
cover.
-Remove the rubber cover from the inspection
hole on the R/ H side of the gearbox.
-Using a
proper tool, turn the alternator so as
to
br ing the right piston to T.D. C.
(closed valves); observe that the mark .. D .. ap-
pears in the middle of the inspection hole.

- Fit the tool with arrow 14927500 ( 26 fig. 64)
onto the valve gearing cover and lock it by me-
ans of a screw.
-Undo the bolt securing alternator to crank-
shaft, aUgn the mark PMS (T.O.C .) with the tool
arrow then fit the degree plate
14927400 (25
fig. 64) onto the alternator itself, secure then
degree plate and alternator to the crankshaft by
means of the screw.
-Check through the inspection ho
le that the
reference mark . 0. is always aligned with the
mark in the center of the hole rim.
-Rotate the alternator (with degree plate)
128"
Clockwise, starting from the mark .PM$. (T.O.C.)
in line with the tool arrow.
At this stage. under normal conditions, the ex-
haust valve of right cylinder must start opening.
After this checking and provided everything is
normal, it is necessary to re-set the working
clearance between rocker and valve at 0,
22 mm .
Then fit the rocker box covers, securing them by
means of proper screws and the rubber cover
onto the gearbox inspection hole. Remove the
arrow tool and the degree plate, lock the bolt
securing alternator to crankshaft. re-fit the alter-
nalor cover onto the valve gearing cover and the
spark plugs.
179

LUBRICATIONS
ENGINE LUBRICATION
D_ripllon
This type of engine fits an oil filter which, in
addition to a wire gauze filter, is provided also
with a cartridge filter (to be replaced every 15000
km about). This ensures an almost integral filte-
ring before the oil passes in the pump and lubfi·
eating channels.
011 Sump (see f;g.218)
The oil sump fits:
A - Filter cartridge. replaceable.
B - Magnetic oil drain plug.
o - Wire gauze filter.
E - 011 pressure reHef valve.
Checking the oU level In the engine
(see fig. 354)
Every 500 km check the oil level in the crank-
case
(it must be nearly at the max. mark stam-
ped on the cap filler dipstick
.. A,,).
In case of lower level, fill with oil having recom-
mended features.
Check the all level after the engine has run for
• few mlnut.. and fully screw the cap flUer
dlplUck .. Alt.
Changing the 011 (see fig. 354)
After the first 500 + 1.000 km and later on every
3.000 km change the engine oil. The oil has to be
replaced when the engine
II warm. Allow all the
old oil to drain before intrucing fresh oiL
.. A. oil filler cap.
.. 8. oil drain plug.
Required O.ty:
It 3 of oil AGIP SINT 2000 SAE
10 W/ 50.
Replacing the flHer cartrfdge (see fig. 218)
Every 15.000 km (five oil changes) replace the
filter cartridge
.. A. proceeding as follows:
-Undo the drain plug
,, 8,. and let the oil drain
from the sump.
-Undo the securing screws and remo
ve the
sump
.. C. from the crankcase, using a nylon
hammer. The sump fits: the filter cartridge
«A» ,
the wire gauze .. D. and the oil pressure relief
valve
.. E ,..
-Unscrew the filter cartridge "A ,. from the
sump
.. e. and replace it by an original one. It is
advisable to wash the wire gauze filter .. D. too.
180
By re·fitting the sump onto the crankcase ra--
member to replace also the gasket between
sump and crankcase.
Wire gauze filter (see fig.
218)
The wire gauze filter .. 0 ,. is secured to the sump
.. C .. by means of a bolt with a securing plate.
When replacing the filter cartridge
.. A. it is advi·
sable to remove also the filter .. D. to wash it in
gasoline and b
low it out with compressed air.
011 p ..... ure relief valve (see fig. 218)
The ojl pressure relief valve .. E .. is screwed on
the sump
.. C•. It is calibrated to allow a pressure
of 3,8
-;.. 4,2 kp/cm2•
In case of higher pressure, this valve opens thus
adjusting the pressure to the correct limits.
Shoud the calibration be higher or lower , adjust
the valve in such a way
that it opens exactly at
the correct pressure. This Is done by removing
one or more shims over the spring if calibration
is higher or by adding one
or more shims over
the spring if calibration is lower.
GEARBOX LUBRICATION (see fig. 84)
Checking the 011 level
Every 3.000 km check that the oil level is nearly
at the inspection hole
.. 8•. In case of lower level
fill with oil of recommended features.
Changing the
011
Every 10.000 km or so change the oil in the gear
box.
This operation has to be carried out when the
oil is still warm and easy to drain. Let all the old
oil to drain before introducing fresh oil.
.. A. oil filler cap.
.. 8. level inspection plug.
.. C. drain plug.
Required O.ty: It 0,750
of oil Agip F. 1 Rotra MP
SAE 90 .
REAR DRIVE BOX LUBRICATION (see fig. 355)
Checking the 011 level
Every 3.000 km check that the oil level is nearly
at the inspection hole
.. A•. tn case of lower level
fill oil of recommended features.