Instructions
Ride the Asia Boat to a platform containing several gears.
Use your paintbrush to fill in with color the gears on the left side of the platform.
Put paint thinner on the big middle gear. This should now make all of the gears operational.
Step on a nearby switch to start the gears moving. This will activate the Dragon Bridge, which allows access to the nearby temple.
Take the boat back to land and cross the bridge.