THE HEAD LUBRICATION CHANNEL IS PROVIDED WITH
A SHUTTER JET; THIS GIVES A "LOW PRESSURE" HEAD
LUBRICATION; THIS CHOICE WAS MADE TO REDUCE
THE OIL TEMPERATURE IN THE SUMP. THE JET CLOG-
GING IMPAIRS THE HEAD LUBRICATION AND THE TIM-
ING MECHANISMS. A JET FAILURE CAUSES A DE-
CREASE OF THE MAIN BUSHING AND CONNECTING ROD
LUBRICATION PRESSURE.
Inspecting the crankshaft plain bearings
- T
o obtain a good bushing lubrication it is necessary
to have both an optimal lubricating pressure (3.2
bar) and a good oil flow rate; the bushings must be
correctly positioned so as not to obstruct the oil
supply channels.
- The main bushings are comprised of two half-
bearings, one with holes and channels for lubrica-
tion whereas the other is solid.
- The solid half-bearing is intended to stand the
thrusts caused by combustion, and for this reason
it is arranged opposite the cylinder.
- To prevent obstructions in the oil feeding chan-
nels, the matching surface of the two half-bearings
must be perfectly perpendicular to the cylinder ax-
is, as shown in the figure.
- The oil feeding channel section is also affected
by the bushings driving depth compared with the
crankshaft axial clearance of the limiting surface.
- Check the inside diameter of the main bushings
in the three directions indicated in the diagram.
- Repeat the measurements for the other bushing
half. see diagram.
- There are three crankcase versions: with RED
main bushings, with BLUE main bushings and with
YELLOW main bushings.
- There is only one type of main bushing housing
hole in the crankcase
The standard bushing diameter after driving is var-
iable on the basis of a coupling selection.
MSS X9 Evolution 250
Engine
ENG - 133
Summary of Contents for MSS X9 EVOLUTION 250
Page 1: ...WORKSHOP MANUAL 618153 MSS X9 Evolution 250 ...
Page 4: ......
Page 6: ...INDEX OF TOPICS CHARACTERISTICS CHAR ...
Page 19: ...INDEX OF TOPICS TOOLING TOOL ...
Page 31: ...INDEX OF TOPICS MAINTENANCE MAIN ...
Page 46: ...INDEX OF TOPICS TROUBLESHOOTING TROUBL ...
Page 52: ...INDEX OF TOPICS ELECTRICAL SYSTEM ELE SYS ...
Page 77: ...INDEX OF TOPICS ENGINE FROM VEHICLE ENG VE ...
Page 80: ...INDEX OF TOPICS ENGINE ENG ...
Page 116: ...Engine MSS X9 Evolution 250 ENG 116 ...
Page 148: ... Remove the maximum nozzle Remove diffuser Engine MSS X9 Evolution 250 ENG 148 ...
Page 172: ...INDEX OF TOPICS SUSPENSIONS SUSP ...
Page 181: ...stand retaining bolt 20 25 MSS X9 Evolution 250 Suspensions SUSP 181 ...
Page 182: ...INDEX OF TOPICS BRAKING SYSTEM BRAK SYS ...
Page 191: ...MSS X9 Evolution 250 Braking system BRAK SYS 191 ...
Page 192: ...INDEX OF TOPICS COOLING SYSTEM COOL SYS ...
Page 193: ...Circuit diagram MSS X9 Evolution 250 Cooling system COOL SYS 193 ...
Page 203: ...Thermostat cover screws 3 4 MSS X9 Evolution 250 Cooling system COOL SYS 203 ...
Page 204: ...INDEX OF TOPICS CHASSIS CHAS ...
Page 215: ...INDEX OF TOPICS PRE DELIVERY PRE DE ...
Page 219: ...INDEX OF TOPICS TIME TIME ...