VESPA GT 200, Руководство по ремонту

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following the procedure previously described for
measuring the crankshaft axial play and
dimensions.
10.11.5 Checking the Main Bearings
- Proper lubrication of the main bearings depends
on them being seated correctly in their
housings, which will avoid obstructing the
lubrication ducts. Not only will this ensure
proper flow of oil, but also proper oil pressure
values 58 psi (4 bar), on which lubrication of the
main bearings depends.
- The main bearings comprise two half-bearings,
one containing holes and channels for
lubrication and the other solid.
- The solid half-bearing bears the load due to
combustion and is, therefore, located at the far
side from the cylinder.
-
In order to avoid obstructing the passage of oil,
the plane of the coupling between the two half-
bearings must be absolutely perpendicular to
the axis of the cylinder, as shown in the figure.
- The depth to which the half-bearings are driven,
in relation to the surface that limits the axial
play of the crankshaft, can also affect the
alignment of the oil ducts.
Standard dimension:
Main bearing bedding-in depth 0.053-0.063 in
( 1.35-1.60 mm )
Note: The main bearings are driven into steel
rings located by interference fit inside both the
crankcase castings, in order to maintain the
position described above.
-
Check the internal diameter of the main
bearings in the three directions indicated in the
figure.
-
Repeat these measurements on the other side
of the lubrication channel in the bearing (see
figure).
Note: Avoid measuring the main bearings internal
diameter on the mating surface of the two half
shells as the ends are relieved to allow distortion
during the bedding.