Derbi Rambla 250 Manual page 118

Engine
Valve seat wear: Outlet guide
Standard diameter: 5.000 ÷ 5.012 mm
Inspecting the valves
- Measure the width of the sealing surface on the valve seats and on the valves themselves.
Sealing surface width: After use: Intake and outlet: 1.6 mm
- If the sealing surface on the valve is wider than the specified limit, damaged in one or more points or
curved, replace the valve with a new one.
CAUTION
DO NOT CHANGE THE VALVE FITTING POSITION (RH - LH).
Characteristic
Valve wear check: Standard: intake and outlet:
0.99 ÷ 1.27 mm
ENG - 118