2001 Edition Yamaha F225A and LF225A Outboards Service Manual, Page 131Get this manual
Cylinder head Valve spring compressor 4: YM-01253 Valve spring compressor attachment 5: YB-06320
Checking the valve springs
1Measure the valve spring free length aReplace if out of specificationValve margin thickness a: Intake: 0.7 mm (0.028 in) Exhaust: 1.0 mm (0.039 in) 3Measure the valve stem diameter bReplace if out of specification
Valve spring free length a: 44.20 mm (1.740 in) 2Measure the valve spring tilt bReplace if out of specificationValve stem diameter b: Intake: 5.4775.492 mm (0.21560.2162 in) Exhaust: 5.4645.479 mm (0.21510.2157 in) 4Measure the valve stem runoutReplace if out of specification