Engine Speed - Yamaha MX250 Service Manual

PERIODIC MAINTENANCE
1
Adjuster
Turn clockwise
Turn counterclockwise
c. Tighten the locknut "1".
Valve adjuster locknut:
7 N·m (0.7 kgf·m, 5.2 lb·ft)
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
6.
Install:
• Cylinder head cover gasket
• Cylinder head cover
Cylinder head cover bolt:
11 N·m (1.1 kgf·m, 8.1 lb·ft)
• Breather hose
• Spark plug
Spark plug:
20 N·m (2.0 kgf·m, 15 lb·ft)
• Spark plug cap

ENGINE SPEED

1.
Warm up the engine for several minutes.
2.
Attach:
• Digital tachometer "1"
Digital tachometer:
YU-39951-B, 90890-06760
3.
Measure:
• High engine speed (with no load)
Out of specification  Adjust.
High engine speed:
3750–3850 r/min
2-13
Valve clearance
Decrease
Increase
New
1
2
3
4
5
6
7
8
9
10