APRILIA RSV4 RR 2017 Service Station Manual page 342

Engine
REPLACE THE VALVES ONE AT A TIME. DO NOT MIX THE COMPONENTS. EACH VALVE MUST
BE INSERTED INTO ITS SEAT, WHICH IS MARKED PRIOR TO REMOVAL.
VALVE STEM DEVIATION
Lift up the valve approx. 10 mm (0.39 in) from its
seat.
Measure the valve stem deviation in two perpen-
dicular directions and position the dial gauge as
shown in the figure.
Characteristic
Valve stem distortion
0.25 mm (0.0098 in)
If the valve stem, when measured with a micro-
meter, is worn to its limit and the clearance ex-
ceeds the specified limit, replace the valve.
Recheck the clearance after replacing the valve.
Characteristic
Intake valve stem diameter
4.985 - 4.965 mm (0.1963 - 0.1954 in)
Exhaust valve stem diameter
4.975 - 4.955 mm (0.1959 - 0.1951 in)
Support the valve with two "V" blocks as shown
and check the run-out with a dial gauge.
If the run-out exceeds the specified limit, replace
the valve.
Characteristic
Valve stem run-out
0.05 mm (0.0020 in)
Position the dial gauge at a right angle to the valve
head face and measure the eccentricity.
If the eccentricity exceeds the specified limit, re-
place the valve.
Characteristic
Valve head eccentricity
0.03 mm (0.0012 in)
ENG - 342
RSV4 RR-RF