

Note
For clarity, the figures show the engine removed from the frame.
Move the piston of the cylinder being checked to tdc of the power stroke: in this condition, all the valves are closed and the timing shafts come in neutral position and, therefore, free to rotate; check to the valve clearance on the cylinder head on which it operates.
Checking the opening clearance
Using a feeler gauge, check the clearance between the opening rocker arm (a) and the lowest point of the camshaft lobe (b), taking care not to compress the rocker arm return spring.
The value must be within the specified ones (sect. 3 - 1.1, Timing system/valves).
If not, remove the opening adjuster (3), as described in paragraph "removing the valves" (sect. 9 - 4.5), And replace it with one of suitable height to obtain the prescribed clearance.
Note
Opening rocker arm shims measuring 1.80 To 3.45 Are available as replacement parts: the size is punched on the shim.

Checking the closing clearance
Using a feeler gauge, check the clearance between the closing rocker arm (c) and the highest point of the camshaft lobe (d).
The value must be within the specified ones (sect. 3 - 1.1, Timing system/valves).
If not, remove the closing adjuster (1), as described in paragraph "removing the valves" (sect. 9 - 4.5), And replace it with one of suitable height to obtain the prescribed clearance.
Note
Closing rocker arm shims measuring from 2.2 To 4.5 Are available as replacement parts: the size is punched on the shim.

Checks and adjustments
Checking valve liftRemoval of the throttle twistgrip
Peel back the rubber sleeve (a) protecting the throttle control cables.
Undo the screws (b) of the throttle grip (6) and open the command.
Disconnect the throttle grip cables (10) by unhooking the cable ends (c) from
their seats.
Remove the throttle twistgrip (6) from the handlebar.
...
General safety rules
Carbon monoxide
When a maintenance operation must be performed with the engine running, maker
sure that the working area is wellventilated.
Never run the engine in an enclosed space.
Warning
Exhaust fumes contain carbon monoxide, which is a poisonous gas that
can cause unconsciousness or e ...
Checking the camshafts and supports
Check the cam contact surfaces for scratches, grooves, steps and waving.
Worn cams are frequently the cause of poor timing, which leads to loss of engine
power.
Place the camshaft between two centres and check the run-out on the areas
indicated using two dial gauges.
Service limit: 0.1 ...