APRILIA QUASAR 125 2003, Workshop Manual

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QUASAR 125-180
PERIODIC MAINTENANCE
2 - 19 -
00
Release 00/2003 - 09
2
1
50 ÷ 60 mm
3
3
5 5
4 4
2.18 DRIVE CHAIN
An excessive slackening of the chain may cause noise or make the chain
rattle.
Periodically check the slack and adjust it if necessary.
Incorrect maintenance may cause the untimely wear of the chain and/or
damages to the front and/or the rear sprocket.
NOTE
Perform the maintenance operations more frequently if the vehicle is
used in rainy or dusty areas, on uneven surfaces or on racetracks.
CHECKING THE SLACK
To check the slack, proceed as follows:
"
Stop the engine.
"
Loosen and remove screw (1).
"
Remove chain tensioner (2). Take care not to damage the return spring.
"
Make sure that the vertical oscillation, in an intermediate point between front
and rear sprocket in the upper part of the chain, is about
50~60 mm .
"
Move the vehicle forwards, or turn the wheel, in order to be able to check
the vertical oscillation of the chain even when the wheel turns; the slack
must be constant in all the rotation phases of the wheel.
"
Refit chain tensioner (2) with spring and tighten screw (1).
If in some positions the slack is higher than in others, this means that
there are crushed or seized links; in this case, replace the chain, see
6.7.1 (DISASSEMBLING THE CHAIN). To prevent the risk of seizures,
lubricate the chain frequently.
If the slack is even, but exceeding the maximum limit allowed, adjust it.
ADJUSTMENT
If after the check it is necessary to adjust the chain tension, proceed as
follows:
"
Slacken the four screws (3).
"
Partly slacken the two lock nuts (4) on the tensioners (5).
"
Adjust the chain tension with the tensioners (5).
"
After the adjustment, tighten the lock nuts (4).
"
Tighten the four screws (3).
"
Check that the slack is now within the maximum limit allowed.
CHECKING THE DRIVING CHAIN, FRONT AND REAR SPROCKET WEAR
Further, check the following parts and make sure that chain, front and rear
sprockets do not show:
- damaged rollers;
- loose pins;
- dry, rusty, crushed or seized links;
- excessive wear;
- sprocket or teeth excessively worn or damaged.
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