Inspecting The Valve Sealings/Housings - Derbi GP1 125-250 c.c. Workshop Manual

I I
NSPECTING THE VALVE SEALINGS NSPECTING THE VALVE SEALINGS
- Insert the valves into the head.
- Alternately test the intake and exhaust valves.
- The test should be carried out by filling the manifold with
fuel and checking that the head does not bleed from the
valves, when pressed by your fingers only.
I
NSPECTING THE VALVE HOUSINGS S C G
- Check the width of the impression on the valve seat «V»;
max wear limit 1.6 mm.
- Clean the valve guides of any carbon residues.
- Measure the inside diameter of each valve guide.
- Measure according to the rocker thrust direction at three
different heights.
- If the valve seat impression width or the valve,guide diame-
ter are larger than the prescribed values, replace the head.
Characteristic
Wear of valve seats: Intake guide
Admissible limit:
5,022
Wear of valve seats: Intake guide
Standard diameter:
5,000 ÷ 5,012 mm
Wear of valve seats: Exhaust guide
Admissible limit
5,022
Wear of valve seats: Exhaust guide
'Standard diameter:
5,000 ÷ 5,012 mm
118
OUS GS