Checking Valve Springs; Checking Valve Spring Seat; Checking The Cylinder Head - Husqvarna FC 450 2014 Repair Manual

17 ENGINE
17.4.27

Checking valve springs

17.4.28

Checking valve spring seat

17.4.29

Checking the cylinder head

-
Check sealing seat
Valve
Intake sealing seat width
Valve
Exhaust sealing seat width
If the sealing area is not in the center of the valve seat or deviates from the
specified value:
-
Rework the valve seat.
302808-10
-
Check the valve springs for breakage and wear (visual check).
If the valve spring is broken or worn:
-
Change the valve spring.
-
Measure the length of the valve springs.
Valve spring
Intake minimum length (without
valve spring seat)
Valve spring
304678-10
Exhaust minimum length (without
valve spring seat)
If the measured value does not meet specifications:
-
Change the valve spring.
-
Check the valve spring seat for breakage and wear (visual check).
If the valve spring seat is broken or worn:
-
Change the valve spring seat.
-
Measure the thickness of the valve spring seat.
Valve spring
Valve spring seat
If the measured value does not meet specifications:
-
Change the valve spring seat.
304679-10
-
Check exhaust valve guides
I
Limit plug gauge (59029026006) (,r p. 221)
If the special tool is easy to insert in the valve guide:
-
Change the valve guide and valve.
-
Check intake valve guides
I
Limit plug gauge (59029026006) (,r p. 221)
If the special tool is easy to insert in the valve guide:
-
Change the valve guide and valve.
-
Check the sealing area of the spark plug thread and the valve seats from damage
and cracking.
If there is damage or cracking:
-
Change the cylinder head.
on the valve.
6)
2.00 mm (0.0787 in)
2.00 mm (0.0787 in)
40. 7 mm (1 .602 in)
1
40. 7 mm (1 .602 in)
1
1.8 mm (0.071 in)
O
using the special tool.
8
using the special tool.
157