Oil quality is a major contributor to your engine's performance and life. Always select good quality engine oil. Suzuki recommends the use of suzuki performance 4 motor oil or equivalent engine oil. Use sf/sg or sh/ sj with jaso ma in api (american petroleum institute) classification.

Api: american petroleum institute jaso: japanese automobile standards organization
Sae engine 011 viscosity
Suzuki recommends the use of sae 1 ow-40 engine oil. If sae 10w-40 engine oil is not available, select an alternative according to the following chart.

Jaso T903
The jaso t903 standard is an index to select engine oils for 4- stroke motorcycle and atv engines. Motorcycle and atv engines lubricate clutch and transmission gears with engine oil. Jaso t903 specifies performance requ irements for motorcycle and atv clutches and transmission.
There are two classes, ma and mb. The oil container has following classification for confirming the standard.

Energy conserving
Suzuki does not recommend the use of "energy conserving" oi ls. Some engine oils which is api sh or greater has "energy conserving" indication in api classification doughnut mark.
These oils can affect engine life and clutch performance.
Fuel
Engine coolant solutionFuel injection system description
Gsx-r1000 motorcycles are equipped with a fuel injection system for emission
level control. This fuel injection system
is precision designed, manufactured and adjusted to comply with the applicable
emission limits. With varying engine
conditions, all of the fuel injection volumes are precisely ...
Rear shock absorber bearing removal and installation
Removal
Remove the rear shock absorber. Refer to “rear shock absorber removal
and installation” .
Remove the spacer (1).
Remove the rear shock absorber bearing with the
special tool.
Special tool
(a): 09943–88211 (pinion bearing
installer)
Installation
C ...
Windshield cleaning
Clean the windshield with soft
cloth and warm water with mild
detergent. If scratched, polish
with a commercially available
plastic polish. Replace the windshield
if it becomes scratched or
discolored so as to obstruct view.
When replacing the windshield,
use suzuki replacement windshield. ...