Yamaha RST90A Offroad Vehicle User Manual


 
Control functions
37
Your Yamaha engine has been designed to
use regular unleaded gasoline with a pump
octane number [(R+M)/2] of 86 or higher, or a
research octane number of 91 or higher.
NOTICE
ECS00084
Oxygenated fuels (gasohol) containing
a maximum 10% of ethanol (E10) can be
used, although richer jetting may be re-
quired to prevent engine damage. Con-
sult a Yamaha dealer. Gasohol
containing methanol is not recommend-
ed.
Make sure that snow or ice does not en-
ter the fuel tank when refueling.
Do not use alcohol deicers or water ab-
sorbing additives with oxygenated fuel.
The fuel tank should be filled with the
recommended gasoline. The use of oth-
er gasoline will cause severe damage to
internal engine parts, such as the valves
and piston rings, as well as to the ex-
haust system.
ESU14001
Suspension
The suspension can be adjusted to suit rider
preference. Softer settings, for example, may
provide greater rider comfort, while harder
settings may allow more precise handling and
control over certain types of terrain or riding
conditions.
If you are not familiar with suspension adjust-
ments, have a Yamaha dealer make these
adjustments.
WARNING
EWS00151
Read and understand the following infor-
mation before handling shock absorbers
that contain highly pressurized nitrogen
gas.
Do not tamper with or attempt to open
the cylinder assemblies.
Do not subject the shock absorbers to
an open flame or other high heat source.
This may cause the unit to explode due
to excessive gas pressure.
Do not deform or damage the cylinders
in any way. Cylinder damage will result
in poor damping performance.
Do not dispose of a damaged or worn
out shock absorber yourself. Take the
shock absorber to a Yamaha dealer for
any service.
TIP
Use the special wrench included in the own-
ers tool kit to make the suspension adjust-
ments. If the tool kit for your model does not
include the special wrench, the special
wrench can be obtained at a Yamaha dealer.
ESU10894
Adjusting the spring preload of the
front shock absorbers
WARNING
EWS00720
The spring preload of the left and right
shock absorbers must be adjusted to the
same setting. Uneven settings can cause
poor handling and loss of stability.
The spring preload can be adjusted by turning
the adjusting nuts.
Adjust the spring preload as follows.
1. Loosen the locknut.
Recommended fuel:
REGULAR UNLEADED GASOLINE
ONLY
Fuel tank capacity:
RS90GT 35.6 L (9.41 US gal,
7.83 Imp.gal)
RS90LTGT 35.6 L (9.41 US gal,
7.83 Imp.gal)
RST90 39.3 L (10.38 US gal,
8.65 Imp.gal)
RST90GT 35.6 L (9.41 US gal,
7.83 Imp.gal)
U8JA11E0.book Page 37 Monday, June 14, 2010 10:22 AM