Air Valve Spring - Yamaha YBR 125 Service Manual

Check and repair
3.Check:
Working face of air valve
Corrosive pitting or wear→polishing the surface
Air valve rod end
Mushroom shape or diameter more than other part of air
valve rod→replacing
4. Measure:
Run-out tolerance (air valve rod)
Exceeding specified value range→Replacement
Run-out tolerance

Air valve spring

1.Measure:
Free length a (air valve spring)
Exceeding specified value range→Replacement
Free length of air vlave spring:
4 - 22
Less than0.01 mm
Standard: 32.28 mm
Limitation: 31.90 mm
ENG