APRILIA Tuono V4 1100 Factory Service Station Manual page 362

Engine
•
Remove the intake and exhaust cam-
shafts.
If the two camshafts are timed correctly, the ex-
haust camshaft gear tooth (indicated with a dot) is
meshed with the trough of the intake camshaft
gear (indicated with two dots).
Inspecting camshafts
CAMSHAFT TOOTHED WHEEL CHECK
•
Check that the camshaft gear works properly: if it is damaged or does not move smoothly,
replace the timing chain and the camshaft gear.
CAMSHAFT LOBES
•
Check that they do not show blue colouring, cracks or scratches; otherwise, replace the
camshaft, gear and chain.
•
Fasten the camshaft horizontally, as
shown in the figure, and make it spin to
check the eccentricity with a dial
gauge; if necessary, replace the part.
Characteristic
Maximum camshaft axial clearance (intake/
outlet)
0.3-0.1 mm (0.012-0.004 in)
Check the timing chain for damage or stiffness
while moving.
If necessary, replace the timing chain together with
the camshaft gears.
Check the timing chain guide sliders for damage.
If necessary, replace the parts.
ENG - 362
Tuono V4 1100 Factory