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Page N 1
(N
TIMING
NOTE.- When checking and adjusting valve clearances the engine should
be turned to bring the respective pistons to T.D.C. on compression.
the fuel pump adaptor in line with the scribed line
on the pointer of the fuel pump.
The timing or resettÏl1g of the timing on the
Perkins L4 engine can be simply and expediently
carried out if the following instructions are fol.
lowed.
It is well to rememb:r ..hat if tbc cylinder hcad
has been removed it does not, in any way, affect
the timing of the engine.
Rotate camshaft to bring inlet and exhaust
valves of No. 4 cylinder to rocking position.
With the crankshaft set as described above placc
idler gear in position, ensuring that the timing
marks line up correctly. Replace idlcr gear s"et-
screw, tightcn and lock with tab washer.
..,
VALVE n~G
If for any reason a new camshaft gear bas been
fitted it may be necessary to re-time the engine.
Fit replacement gear as instructed in Section L
and proceed as follows :-
MARKINGS.
The timing gears are marked as shown in Fig. N.1
so that, if for any reason the timing has to be
broken, the engine can easily be re-set to its
original timing.
Tbere are two different markings on the Cuet
pump adaptor.
One is a scribed line marked
with tbe letter .. S" whicb should coincide witb
tbe scribed line on the pointer of the Cuet pump,
wben the engine is set at T .D.C. firing on No. r
cylinder (Sec Fig. N .2).
Bring Nos. I and 4 pistons to T .D.C.
That
T .D.C. bas been obtained on Nos. I and 4 pistons
can be checked by examining the flywheel, or the
crankshaft at the front end where the key for the
fan belt pulley should be at the top of its periphery.
Remove idler gear.
Tbe altemative scribed line on tbe fuel pump
adaptor denotes spill timing, 21° B.T.C. In the
case of L4 engines fitted to the Marshall Crawler
Tractor, the spill timing is 24° B.T.D.C.
To obtain access to the fuel pump markings it
is necessary to remove the inspection plate situated
on the left hand si de of the timing case.
To Re-set Engine to its Original Timing.
Remove atomisers.
Brlng Nos. I and 4 pistons to the top. That
T ..D.C. bas been obtained can he checked by
examining tbe flywheel or tbc front end of the
crankshaft, where the key of the fan belt pulley
should he at tbc top of its periphcry.
Set fucl pump gear with scribed linc ., S" on
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