If the valve is open, replace the thermostat with a new one.

The thermostat must be completely submerged and must not touch the container sides or bottom. Suspend an accurate thermometer [B] in the water so that the heat sensitive portions [C] are located in almost the same depth.
It must not touch the container, either.
If the measurement is out of the specified range, replace the thermostat with a new one.
Thermostat Valve Opening Temperature
58
62°C (136
144°F)

Thermostat Installation
Hoses and PipesCable Removal
Remove:
Air Cleaner Housing (see Air Cleaner Housing Removal
in the Fuel System (DFI) chapter)
Right Lower Fairing (see Lower Fairing Removal in the
Frame chapter)
Loosen the nuts [A], and slide the lower end of the clutch
cable to give the cable plenty of play.
Screw in the ...
Brakes
Brake Wear Inspection
Inspect the brakes for wear. For each
front and rear disc brake caliper, if the
thickness of either pad is less than
1 mm (0.04 in.), replace both pads
in the caliper as a set. Pad replacement
should be done by an authorized
Kawasaki dealer.
A. Lining Thickness
B. ...
Engine Oil Change
Situate the motorcycle so that it is vertical after warming
up the engine.
Remove the engine oil drain bolt [A] to drain the oil.
The oil in the oil filter can be drained by removing the filter
(see Oil Filter Replacement).
Replace the drain bolt gasket [B] with a new one.
Tighten t ...