Checking The Valve Guides; Checking The Cylinder Head - MOTO GUZZI GRISO 850 2007 Service Station Manual

GRISO 850

Checking the valve guides

Use a punch to extract the valve guides from the
heads.
The valve guides should be replaced only if the
clearance between them and the stem cannot be
eliminated by simply replacing the valves.
To refit the valve guides on the head, follow this
procedure:
•
Heat the head in an oven at approxi-
mately 60°C (140°F).
•
Lubricate the valve guide.
•
Fit the circlips.
•
Press a punch with the valve guides.
•
Use a reamer to bore the holes the
valve stems slide through so that the
inside diameter is at the prescribed val-
ue. The interference between the seat
on the head and the valve guide must
be 0.046 - 0.075 mm (0.0018 - 0.0030
in)
VALVE AND GUIDES COUPLING DATA
CHART (INLET)
Specification
Valve guide inside diameter
mm (in)
Valve stem diameter
Fitting clearance mm (in)
VALVE AND GUIDES COUPLING DATA
CHART (OUTLET)
Specification
Valve guide inside diameter
mm (in)
Valve stem diameter mm (in)
Fitting clearance mm (in)

Checking the cylinder head

Check that:
Desc./Quantity
8.000 ÷ 8.022 (0.3150 ÷
0.3158)
7.972 ÷ 7.987 (0.3139 ÷
0.3145)
0.013 ÷ 0.050 (0.0005 ÷
0.0020)
Desc./Quantity
8.005 ÷ 8.022 (0.3152 ÷
0.3158)
7.965 ÷ 7.980 (0.3136 ÷
0.3142)
0.025 ÷ 0.057 (0.0010 ÷
0.0022)
Engine
ENG - 111