Yes, definitely adjust the valves. Watch a YouTube video on GY6 150 valve adjustment, your engine will be the same except for the number of bolts holding on the valve cover. The temperature sensor is a small brass cylinder that screws into the head just below the right side of the valve cover. It has 2 wires going to it and a white heat sheath over the wire to protect it. It plugs into the wiring harness . Yours won't have the plastic piece and zip tie over the wire, it was part of my experiment adding a resistor to the circuit.