1985-1986 Honda ATC250R Shop Manual, Page 127Get this manual
COOLING SYSTEM
COOLING SYSTEM INSPECTION
Pressure test the radiator capReplace the radiator cap if it does not hold pressure, or if relief pressure is too high or too lowIt must hold specified pressure for at least six secondsNOTE on the- tester, apPlY] to sealing surfaces_
RADIATOR CAP
RADIATOR CAP RELIEF PRESSURE: 110-140 kPa 0.1-1.4 kgcm16-20 psi)
COOLING SYSTEM TESTER (COMMERCIALLY AVAILABLE) COOLING SYSTEM TESTER Pressurize the radiator, engine and hoses, and check for leaksCAUTION