Mercury Workshop Service and Repair Manuals

Valve: Specifications

Clearance

To Guide ..........................................................................................................................................................................................  See: Valve Guide
Lash (Collapsed Tappet) .........................................................................................................................................  0.50-1.11 mm (0.019-0.043 inch)

Face

Angle ...................................................................................................................................................................................................................  45.5°
Margin Thickness

Exhaust  and Intake ................................................................................................................................................................  0.79 mm (1/32 inch)

Runout, Maximum .....................................................................................................................................................................  0.05 mm (0.001 inch)

Head Diameter

Intake ..............................................................................................................................................................................................  35 mm (1.38 inch)
Exhaust ...........................................................................................................................................................................................  30 mm (1.18 inch)
Gauge Diameters ................................................................................................................................................ 31 and 24.5 mm (1.22 and 0.96 inch)

Lift @ Zero Lash (Theoretical)

All ..............................................................................................................................................................................................  9.80 mm (0.388 inch)

Stem Diameter

Intake ...............................................................................................................................................................  5.975-5.995 mm (0.2350-0.2358 inch)
Exhaust ............................................................................................................................................................  5.950-5.970 mm (0.2343-0.2350 inch)

Stem Refinishing, Max ....................................................................................................................................................................  0.25 mm (0.010 inch)