Yamaha RS90K Manuel D'atelier page 296

DRIVE CHAIN HOUSING
2. Inspect:
• Drive sprocket 1
• Driven sprocket 2
• Chain tensioner 3
Pitting/wear/damage → Replace.
3. Measure:
• 14 link section a of the drive chain
Using a spring scale, pull on the drive chain
with 36 kg (80 lb) of force b.
Out of specification → Replace the drive
chain.
Maximum 14 link drive chain section
length:
133.35 mm (5.25 in)
Limit: 137.35 mm (5.41 in)
NOTE:
• Measure the length between drive chain pin 1
and E as shown.
• Perform this measurement at two or three differ-
ent places.
If replacement is necessary, always replace the
chain and the sprockets as a set.
4. Inspect:
• Drive chain 1
Stiffness → Clean and lubricate or replace.
• Drive chain plates 2
Damage/wear → Replace the drive chain.
Cracks → Replace the drive chain.
5. Measure:
• Brake disc thickness a
Measure the brake disc thickness 1 ~ 3 mm
(0.04 ~ 0.12 in) from the edge of the brake
disc.
Out of specification → Replace.
Minimum thickness:
5.0 mm (0.20 in)
4-19
POWR
TR