What is dangerous/max engine temperature on the 97 Honda XR600r. When looking at my Vapor digital speedometer which tracks my engine temperature as well; I noticed my engine temperature on a 90 degree day reach 550 degrees and climbing when over 60mph. Is that a bad thing? (They are single-cylinder air-cooled 4 strokes engine.) Also, my 1997 XR600R is a 5 gallon tank and I was trying to figure out how many liters or gallons are in the reserve tank?