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 solutionSpecifications
Service data
Fi sensors
Tightening torque specifications
Reference: for the tightening torque of fastener not specified in this
section, refer to “tightening torque list” in section 0c . ...
Precautions
Precautions for driveline / axle
Refer to “general precautions” in section 00 (page 00-1).
Never inspect or
adjust the drive chain while the engine is running.
Caution
do not use trichloroethylene, gasoline or such similar
solvent. These fluids will d ...
Throttle body disassembly and assembly
Refer to “throttle body removal and installation” .
Disassembly
Caution
identify the position of each removed part.
Organize the parts in their respective groups
so that they can be reinstalled in their
original positions.
Disconnect the fuel feed hose (1), isc valve ho ...