Checking The Valves; Checking The Valve Springs; Checking The Lower Valve Spring Retainer - KTM 450 EXC-R EU Repair Manual

30/ENGINE - WORK ON INDIVIDUAL PARTS

Checking the valves

Info
The valve stem is chrome-hardened, and wear normally takes place in the valve guide.
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Checking the valve springs

Checking the lower valve spring retainer

Check for valve retainer run-out.
Valve
Run-out on valve plate
» If the measured value does not equal the specified value:
Change the valve.
200193-10
Check sealing seat
Valve
Sealing seat width, intake
Valve
Sealing seat width, exhaust
» If the sealing area is not in the center of the valve seat or if it differs from the
specified value:
Machine the valve seat.
400373-10
Check the valve springs for breakage and wear (visual check).
» If the valve spring is broken or worn:
Change the valve spring.
Measure the valve spring length.
Valve spring
Minimum length, intake (without
bottom valve spring retainer)
Valve spring
Minimum length, exhaust (without
200190-10
bottom valve spring retainer)
» If the measured value does not equal the specified value:
Change the valve spring.
Check the lower valve spring retainer for breakage and wear (visual check).
» If the lower valve spring retainer is broken or worn:
Change the valve spring retainer.
Measure the thickness of the lower valve spring retainers.
Valve spring
Bottom valve spring retainer
» If the measured value does not equal the specified value:
Change the valve spring retainer.
500173-01
0.05 mm ( 0.002 in)
on the valve.
1.5 mm (0.06 in)
2 mm (0.08 in)
46.5 mm (1.83 in)
43 mm (1.69 in)
0.9... 1 mm (0.04... 0.04 in)
87