Extrovert Drive Sprocket (Rst90Tf / Rst90Tfl / Rst90Tfy); Skis And Ski Runners - Yamaha RST90G Owner's Manual

Periodic maintenance and adjustment
 Be careful that water does not enter the
brake fluid reservoir when refilling. Wa-
ter will significantly lower the boiling
point of the fluid and may result in vapor
lock.
ECS01051
NOTICE
Brake fluid may damage painted surfaces
or plastic parts. Always clean up spilled
fluid immediately.
As the brake pads wear, it is normal for the
brake fluid level to gradually go down. A low
brake fluid level may indicate worn brake
pads and/or brake system leakage; therefore,
be sure to check the brake pads for wear and
the brake system for leakage. If the brake flu-
id level goes down suddenly, have a Yamaha
dealer check the cause before further riding.
Changing the brake fluid
EWS00472
WARNING
Make sure that the brake fluid and the fol-
lowing parts are replaced by a Yamaha
dealer.
Brake fluid replacement is necessary when
the following components are replaced dur-
ing the periodic maintenance or if they are
damaged or leaking.
 All oil seals of the master cylinder and cali-
per cylinder
 The brake hose
ESU14271
Extrovert drive sprocket
(RST90TF / RST90TFL /
RST90TFY)
Check the extrovert drive sprocket for wear
and damage. Replace if necessary.
86
To measure the drive sprocket wear
Measure the drive sprocket tooth width at the
measuring line shown. If the tooth width is 13
mm (0.51 in) or less, replace the drive sprock-
et.
1. Drive sprocket tooth
2. Measuring line
3. Drive sprocket tooth width
ESU14661

Skis and ski runners

Checking the skis and ski runners
Check the skis and ski runners for wear and
damage. Replace if necessary.
ECS00561
NOTICE
Avoid scratching the skis when loading
and unloading the snowmobile, when rid-
ing in areas with little or no snow, or on
sharp edges such as concrete, curbs, etc.
This will wear or damage the skis.
1
1. Ski runner wear limit
1
2
3