Beta RR 4T-250, Workshop Manual

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47
6 - Motore
Release 00 Date 02/2005
F
7
11
6
8
9
10
Gearshift mechanism
Gearshift forks 1
Check wear at ends A . When the forks are new, their thickness
ranges from 4.8 to 4.9 mm. The wear limit is 4.6 mm.
Desmodromic mechanism 2
Check the wear of profiled grooves B .
Check the desmodromic mechanism support in ball bearing 3 .
Ball bearing 3
Check that it can turn smoothly.
Bushes 4
Ensure that the bushes present no dents or cracks.
Fork guide rods 5
Check the offset of the rods on a flat surface. Check for signs of
scoring or seizure. The gearshift forks should slide freely on the
guide rods.
Selector 6
Check wear at return points C .
Check the wear of selector return surface D (if the surface is
deeply worn, replace the selector).
Check that guide pin
E is firmly seated and not worn.
Gearshift mechanism
Preassemble the shaft of the gearshift mechanism and measu-
re clearance
F between selector 6 and the guide plate. The play
should be 0.40 - 0.80 mm.
Preassembling the shaft of the gearshift mecha-
nism
– Clamp the short end of the shaft of the gearshift
mechanism in a vice (use protective jaws).
– Fit selector 6 with the guide pin facing downwards
and then attach the guide pin to the guide plate.
– Fit compression spring 7 .
– Fit spring holding bush 8 , top it with return spring
9 with the bent end facing upwards and then atta-
ch it to pin 11 (see figure).
– Fit thrust washer 10 .
1
1
2
B
3
4
4
6
7
C
D
E
8
9
10
4
A
5
5
1