146
sian stroke. Rotate the crankshaft one full
turn.
7. Slowly rotate the crankshaft while observing the fuel
in the fuel nipple on the injection pump and the timing
marks on the flywheel.
8. When fuel appears in the spill pipe, the injection tim-
ing mark on the flywheel (A. Fig
ur
e 19) should align with
the reference pointer (B) on the clutch cover. If viewing
marks through the starter hole, the injection timing mark
on the flywheel (A, Fig
ure
20) should align with the ref-
erence mark (B) on the clutch cover.
NOTE
There are two timing marks
[or
each cylin-
der 011 the flywheel: a
mark
for
top
dead
center (TDC)
and
the injection timing mark.
The TDC mark
is identified by a T next to the
mark. Near the TDC mark is another mark,
the injection liming mark, which has no
identifying letters or numbers. The injection
timing mark
is to the right
of
the TDC mark
when viewing the mark through the starter
hole, or to the leli
of
the TDC mark when
viewing the mark through the clutch cover
hole.
9. If the injection timing is not correct, remove the fuel
injection pump as described in this chapte r.
I
D.
Measure the shim pack located between the pump
and engine mounting surface (
Figure
21).
liA
. Injection timing retarded
-If
injection timing is re-
tarded, decrease the shim thickness to advance injection
timing. Decreasing shim thickness D.I mm will advance
injection timing one degree.
11
B. Injection timing advanced- If injection timing is ad-
vanced, increase the shim thickness to retard injection
timing . Increasing shim thickness 0.1 mm will retard in-
jection timing one degree.
C
HAPTER
SEVEN
12, Install the shims and injection pump, then recheck in-
jection timing.
13. On 2GM, 2GM
2D,
3GM, 3GM3
D,
3HM and 3HM35
models-s-Check fuel injection timing for the remaining
cylinders. Use the injection timing mark adjacent to the
2T or 3T marks for the cylinder being checked. If injec-
tion timing is incorrect for the number two or three cylin-
ders, have a Yanmar dealership or diesel fuel injection
shop inspect the injection pump.
FUEL
[
VJECT
OR
Each cylinder is equipped with a fuel injector (f igure
22). Refer to Fuel Inj ector in the Fuel Injection
Fundamentals
section
of
this chapter for information re-
garding fuel injector operation.
Maintaining optimum fuel injector perfonnanec is pri-
marily dependent on using clean fuel. Din or debris in the
fuel is the predominant cause of poor injector perfor-
mance . The injector is also subject to the heat and byprod-
ucts of combu stion. The fuel injector nozzle is protected
from combustion heat by a heat shield. However, heat and
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