Inspecting The Springs And Half-Cones; Refitting The Valves - Derbi GP1 125-250 c.c. Workshop Manual

- Measure the sealing surface width on the valves and valve
seats.
Sealing surface width: after use:
Intake and exhaust: 1.6 mm
- If the valve sealing surface is wider than the prescribed
limit, interrupted in one or more points, or it is bent, replace
the valve.
CAUTION
DO NOT CHANGE THE VALVE ASSEMBLY POSITION (RH-LH)
Characteristic
Valve wear check: standard: intake and exhaust
0,99 ÷ 1,27mm
I I
NSPECTING THE SPRINGS AND HALF NSPECTING THE SPRINGS AND HALF CONES
- Check that the spring upper support plates and half-cones
are free from irregular wear.
R
EFITTING THE VALVES G S
- Lubricate the valve guides with engine oil.
- Place the valve spring rests on the head.
- Using the specific punch, insert the 4 sealing rings alter-
nately.
- Insert valves, springs and plates. Using the specific tool
provided with the special adapter, compress the springs and
insert the half-cones into the relevant seats.
120
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CONES