Camshaft And Valve Specifications; Gear Housing Specifications - Mercury FourStroke 2.5 Service Manual

Master Specifications

Camshaft and Valve Specifications

Camshaft
Runout limit
Cam lobe height (intake and exhaust)
Upper bearing O.D.
Lower bearing O.D.
Valve spring free length
Valve spring tilt limit
Valve guide
Intake
Exhaust
Valve stem O.D.
Intake valve
Exhaust valve
Valve stem to valve guide clearance
Intake
Exhaust
Valve seat angles
First
Second
Third
Valve stem seal color
Intake
Exhaust
Valve seat width (intake and exhaust)
Valve to rocker arm clearance
Intake
Exhaust

Gear Housing Specifications

Gear ratio
Model 2.5/3.5
Gear housing capacity
Gear lubricant type
Pinion teeth
Forward gear teeth
Clutch
Forward gear backlash
Propeller drive system
Propeller shaft trueness serviceability limit
Page 1A-6
Camshaft and Valve Specifications
Gear Housing Specifications
Premium or High Performance Gear Lubricant
0.03 mm (0.0012 in.)
23.78–24.04 mm (0.94–0.95 in.)
11.95–11.97 mm (0.4705–0.4713 in.)
12.95–12.97 mm (0.5098–0.5106 in.)
33.2–35.0 mm (1.307–1.378 in.)
2 mm (0.079 in.)
5.51–5.55 mm (0.2169–0.2185 in.)
5.51–5.57 mm (0.2169–0.2193 in.)
5.45–5.47 mm (0.2146–0.2154 in.)
5.44–5.46 mm (0.2142–0.2150 in.)
0.018–0.070 mm (0.0007–0.0028 in.)
0.025–0.080 mm (0.0010–0.0031 in.)
30°
45°
60°
Black
Green
1.0–2.0 mm (0.0394–0.0787 in.)
0.06–0.14 mm (0.0024–0.0055 in.)
0.11–0.19 mm (0.0043–0.0075 in.)
2.15:1
180 mL (6.1 fl oz)
13
28
Dog type (forward ‑ neutral)
0.050–0.152 mm (0.002–0.006 in.)
Drive (shear) pin
0.152 mm (0.006 in.) maximum
90-8M0065421 NOVEMBER 2012