R1040 MAINTENANCE MANUAL
Page 36 of 48
tension with the help of tension adjusting screw provided on the fan driving arrangement.
5.6
Adjustments
5.6.1
Checking and adjusting valve clearance
The valve clearance is the requisite gap between the rocker arm toe and valve stem end. See
Fig 5.6.1 below. Engine performance and power output depend on its correct setting, which
can be done by a skilled mechanic according to the instructions below -
Fig 5.6.1
Checking Valve Clearance
•
Check clearance when engine is cold. (At room temperature)
•
Remove the rocker cover.
•
Turn crankshaft until the valves of the cylinder (on which the clearance is being
checked) are “overlapping” (exhaust valve about to close, inlet valve about to
open).
•
Then continue turning the crankshaft through 360° (one complete revolution).At this
position both valves are closed.
•
Insert a feeler gauge of 0.25 mm in the gap between rocker arm toe and valve for both
inlet. The valve clearance is correct when the filler gauge can be inserted with a slight
drag. Failing this, the valve clearance must be readjusted as follows –
Adjusting valve clearance
-
•
Loosen lock nut of adjusting screw through one or two turns and adjust the screw with
screwdriver so that, when locknut is retightened, the feeler gauge of 0.25 mm can be
inserted and with drawn with slight drag. (Fig 5.6.2).
