FUEL SYSTEM
7-32
TNV DI Service Manual
Checking and Adjusting Fuel Injection Timing
Figure 7-41
Note: The following references to the direction-
of-rotation are facing the coolant pump
end of the engine and are adjusted by
turning the crankshaft pulley.
6. Using a wrench on the crankshaft pulley bolt,
rotate the crankshaft in a clockwise direction
while looking through the flywheel inspection
port (Figure 7-42, (1)). Rotate the crankshaft
until the injection timing marks on the flywheel
are visible.
Figure 7-42
7. Typical flywheel markings are as shown in
Note: A typical flywheel will have multiple
timing grids depending on the number of
cylinders. Any grid can be used to check
the fuel injection timing.
The flywheel shown in Figure 7-43 is for a
Yanmar “Standard Specification” DI engine.
Flywheels used on some “OEM Specific” DI
engines may be marked differently. You should
contact that specific OEM for information on the
identification of the timing marks.
1 – 10° BTDC (Before Top Dead Center)
2 – 15° BTDC
3 – 20° BTDC
4 – Direction of Rotation
5 – TDC (Top Dead Center)
Figure 7-43
Note: The TDC (Top Dead Center) mark can
be identified by the cylinder numbers
stamped near the TDC mark on the
flywheel.
If you are uncertain as to the timing degree
designation of the timing marks on the flywheel
timing grid, you can determine the timing degree
designation by measuring the timing grid.
• First measure the distance between two of the
“longer” marks on the timing grid. (They are 5°
apart.) Then measure the distance from the
TDC mark to the first “longer” mark on the
timing grid. Divide that measurement by the
distance between the two “longer” marks. The
resulting answer will tell you how many
degrees there are between the TDC mark and
the first “longer” mark.
0002069
(1)
00020
(1)
(3)
(2)
(1)
(5)
(4)
0002071
1 4
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