PIAGGIO MP3 500 i.e. SPORT, Service Station Manual

Page: 205 / 432

- If the sealing surface of the valve is found to be
interrupted at one or more points or is not flat, re-
place the valve.
- Fit the valves into the cylinder head.
- Alternatively test the intake and exhaust valves.
- The test should be carried out by filling the mani-
fold with fuel and checking that the head does not
ooze through the valves when they are just press-
ed by the fingers.
Inspecting the valve housings
- Remove any carbon deposits from the valve
seats.
- Check the width of the mark on the valve seat
« V » with Prussian blue.
Characteristic
Standard value:
1 - 1.3 mm
Limit allowed:
1.6 mm
- If the width of the mark on the valve seat is larger than the prescribed limits, true the seats with a 45°
milling cutter and then grind.
- Replace the head in case of excessive wear or damage.
Inspecting the valves
- Measure the diameter of the valve stem at the three positions indicated in the diagram.
STANDARD DIAMETER
Specification Desc./Quantity
Inlet: 4.987 ÷ 4.972 mm
Outlet: 4.975 ÷ 4.960 mm
MP3 500 i.e. SPORT Business_LT_ ABS-ASR_EU_USA (2015)
Engine
ENG - 205