2000 Yamaha YFM400FWA(M) Factory Service workshop Manual, Page 27Get this manual
MAINTENANCE SPECIFICATIONS Item Stem runout limit -Standard
Limit 0.01 mm (0.0004 in)
Valve seat width
1.21.4 mm (0.04720.0551 in) 1.21.4 mm (0.04720.0551 in)
Valve spring: Inner spring Free length
39.9 mm (1.57 in) 39.9 mm (1.57 in) 33.6 mm (1.32 in) 33.6 mm (1.32 in) 104.9120.6 (10.7012.30 kg, 23.5827.11 lb) 104.9120.6 (10.7012.30 kg, 23.5827.11 lb)
Set length (valve closed) Compressed pressure (installed)