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 solutionIgnition system check
Remove the spark plugs and
reattach them to the spark
plug caps.
Put the engine stop switch in
the "" position and ignition
switch in the "on" position.
While holding a spark plug
with its base firmly against the
engine, push the electric
starter butt ...
Schematic and routing diagram
Cooling circuit diagram
Water hose routing diagram
Thermostat air bleeder hole
Cushion
O-ring
Radiator heat guard
: be careful not to damage the pawls when removing.
Yellow
marking
White
marking
Clamp end
should face downward
...
Generator inspection
Generator coil resistance
Remove the left side cowling. Refer to “exterior parts removal and
installation” in section 9d .
Disconnect the generator coupler (1).
Measure the resistance between the three lead
wires.
If the resistance is out of specified value, replace the
...