APRILIA TUONO V4 R 2010 Service Station Manual page 274

Engine
•
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 in horizontal po-
sition, 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/ex-
haust)
0.4 mm (0.0016 in)
WARNING
THE EXHAUST CAMSHAFTS OF THE FRONT AND REAR CYLINDER BANKS MUST BOTH BE OF
THE SAME TYPE - EITHER WITH A CONVENTIONAL GEAR OR WITH A SELF-ADJUSTING CAM-
SHAFT GEAR. THE TWO TYPES OF CAMSHAFT ARE INTERCHANGEABLE ON ALL ENGINES
IRRESPECTIVE OF THE CAMSHAFT TYPE ORIGINALLY INSTALLED.
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.
Installing camshafts
NOTE
THIS ENGINE HAS CAMSHAFTS OF THE EXHAUST
VALVES WITH CLEARANCE RECOVERY.
ENG - 274
TUONO V4 R