MOTO GUZZI Stelvio 1200 4V, Service Station Manual

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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 elim-
inated by simply replacing the valves.
To refit the valve guides on the head, follow this procedure:
•
Heat the head in an oven at about 60°C (140°F).
•
Lubricate the valve guide.
•
Fit the circlips.
•
Press the valve guide with a punch.
•
Use a reamer to bore the holes the valve stems slide through so that the inside diameter is
at the prescribed value. 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 GUIDE COUPLING - VALVES (INLET)
Specification Desc./Quantity
Valve guide inside diameter 5.0 ÷ 5.012 mm (0.19685 ÷ 0.19732 in)
Valve stem diameter 4.972 ÷ 4.987 mm (0.19574 ÷ 0.19633 in)
Fitting clearance 0.013 ÷ 0.040 mm (0.00051 ÷ 0.00157 in)
VALVE GUIDE COUPLING - VALVES (OUTLET)
Specification Desc./Quantity
Valve guide inside diameter 5.0 ÷ 5.012 mm (0.19685 ÷ 0.19732 in)
Valve stem diameter 4.960 ÷ 4.975 mm (0.19527 ÷ 0.19587 in)
Fitting clearance 0.025 ÷ 0.052 mm (0.00098 ÷ 0.00205 in)
Checking the cylinder head
Check that:
•
the faying surfaces with the cover and the cylinder are not scored or damaged, jeopardising
a perfect sealing.
•
Check that the tolerance between the valve guide holes and the valve stems is within the
prescribed limits.
•
Check the valve seats are in good conditions.
Engine
STELVIO 4V - 1200
ENG - 42