7. CYLINDER HEAD/VALVES ATV 300/250 Measure compressed force (valve spring) and installed length. Replace if out of specification. Service limits: IN : 10.2011.84 kg (at 18.05 mm) EX : 19.1422.02 kg (at 21.5 mm) Measure the spring tilt. Replace if out of specification. Service limits: IN : 0.8 mm (0.032 in) EX : 1.07 mm (0.428 in) 7-11