Checks - MOTO GUZZI Daytona RS Workshop Manual

11.4

CHECKS

HEADS (Fig. 11-62)
Check that:
■ the surfaces in contact with the cover and with the
cylinder are not scratched or damaged thus
preventing a perfect seal;
■ check that the tolerance between the valve guide holes and the valve stems are within the prescribed limits
(Fig. 11-63);
■ check the state of the valve seats.
INTAKE
Ø 6.972 ÷ 6.987
45°÷ 45° 15'
Ø 33.400 ÷ 33.600 mm
VALVE GUIDE
To extract the valve guides from the heads, use a punch.
The valve guides should be replaced when the clearance between the above and the stems cannot be eliminated
by replacing the valves alone.
To fit the valve guides on the heads:
■ heat the head in an oven to approximately 60°C, then lubricate the valve guides;
■ fit the piston rings;
■ press the valve guides with a punch; pass a stem borer in the holes of the valve stems, to restore the prescribed
internal diameter.
The allowance between the seat on the head and the valve guide must be 0.057÷0.064 mm.
DATA TABLE FOR VALVE AND GUIDE COUPLINGS
Inlet
Exhaust
Ø 7.000 ÷ 7.022
Ø 13.094 ÷ 13.105 mm
internal valve guide dia.
mm
7,000÷7,022
EXHAUST
45° ÷ 45° 15'
Ø 29.400 ÷ 29.600 mm
valve stem dia.
mm
6,972÷6,987
6,965÷6,980
11-62
Ø 6.965 ÷ 6.980 mm
11-63
fitting clearance
mm
0,013÷0,050
0,020÷0,057
87