Yanmar 1GM User Manual page 152

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. Figure 19) should align with
the reference pointer (B) on the clutch cover. If view ing
marks through the starter hole, the injection timing mark
on the flywheel (A, Figure 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 ofthe 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.
ID. Measure the shim pac k 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 inject ion
timing. Decreasing shim thic kness 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 thickne ss 0.1 mm will retard in-
jection timing one degree .
CHAPTER SEVEN
12, Install the shims and injection pump , then recheck in-
jection timing.
13. On 2GM, 2GM2D, 3GM, 3GM3D, 3HM and 3HM35
models-s-C heck fuel injection timing for the remaining
cylinders. Use the inject ion timing mark adjacent to the
2T or 3T marks for the cylinder being checked. If injec-
tion timing is incorrect for the numbe r two or three cylin-
ders, have a Yanmar dealers hip or diesel fuel injection
shop inspect the injection pump.
FUEL [ VJECTOR
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-
gard ing 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 nozz le is protec ted
from combustion heat by a heat shield. However, heat and
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