2006 Honda TRX680 Rincon Factory Service Manual, Page 178Get this manual
COOLING SYSTEM
SYSTEM TESTING
COOLANT (HYDROMETER TEST)
Remove the steering cover (page 3-5)The engine must be Remove the radiator capcool before removing the radiator cap, or severe scalding may result
Test the coolant gravity using hydrometerSTANDARD COOLANT CONCENTRATION: 1:1 (distilled water and the recommended antifreeze) Look for contamination and replace the coolant if necessary
5 10 15 20 25 30 35 40 45 50 55 60
0 (32) 1.009 1.018 1.028 1.036 1.045 1.053 1.063 1.072 1.080 1.086 1.095 1.100