WHOA 160c is 320 fahrenheit. Thats way too hot. You need to be around 120c to be optimum. As for the onboard temp gauges yes and no about being accurate. It all depends on where you place the lead wire hoing around the head. Some have to be as close to the bottom of the head to read good and others have to go up further. What I do is place the wire on the head and get the engine hot. I will use a temp gun to see actual temperature. If the temperature on the onboard reads high you move the wire up 1-2 fins up. You just move the wire around until it gets close to the temp gun. Once you do this you wont need the gun anymore.