Yamaha MZ400, Supplementary Service Manual

Page: 14 / 18

2-5
SPEC
MAINTENANCE SPECIFICATIONS
Model name:
MZ400 MX400
Model code number:
7HSB 7HSJ
Valve: mm (in)
Head diameter “A” IN
31.9–32.1 (1.2559–1.2638)
EX
27.9–28.1 (1.0984–1.1063)
Stem diameter “B” IN 5.948–5.963 (0.2342–0.2348)
EX
5.940–5.955 (0.2339–0.2344)
<Limit> IN
5.918 (0.2330)
EX
5.910 (0.2327)
Stem length “C” IN
88.1 (3.4685)
EX 88.1 (3.4685)
Valve face contact width “D”
IN
0.7–0.9 (0.0276–0.0354)
EX
0.7–0.9 (0.0276–0.0354)
<Limit> IN
1.6 (0.063)
EX
1.6 (0.063)
Valve seat contact width IN
0.7–0.9 (0.0276–0.0354)
EX
0.7–0.9 (0.0276–0.0354)
<Limit> IN 1.6 (0.063)
EX
1.6 (0.063)
Valve seat width IN
0.7–0.9 (0.0276–0.0354)
EX
0.7–0.9 (0.0276–0.0354)
Valve margin thickness IN
1.0–1.4 (0.0394–0.0551)
EX
1.0–1.4 (0.0394–0.0551)
Valve stem runout limit
0.01 (0.0004)
“
θ
”
90°
Valve guide
Guide inside diameter
IN
6.000–6.012 (0.2362–0.2367)
EX
6.000–6.012 (0.2362–0.2367)
Stem to guide clearance IN
0.037–0.064 (0.0015–0.0025)
EX
0.045–0.072 (0.0018–0.0028)
Valve clearance (cold) IN 0.08–0.12 (0.0031–0.0047)
EX
0.08–0.12 (0.0031–0.0047)
Push rod: mm (in)
Runout limit
0.15 (0.0059)