Yanmar 4TNV98, Service Manual

Page: 161 / 246

4TNV98 & 4TNE98 Diesel Engine Section 4. Fuel System 159
Figure 7-37
5. Install a dial indicator (Figure 7-38, (1)) , Mitutoyo
No. 2050SB or equivalent, with a 30mm
extension, Yanmar part no. 158090-51870 or
Mitutoyo No. 303613, into the adapter. Secure
with the Yanmar part no. 23000-013000 plunger
adapter clamp
(Figure 7-37, (1)) at
approximately the mid-point of its travel.
Figure 7-38
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
(Figure7-39, (1)) . Rotate the crankshaft until the
injection timing marks on the flywheel are visible.
Figure 7-39
7. Typical flywheel markings are as shown in
(Figure 7-40, (1)) .
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 7-40 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.
Figure 7-40
(1) 10° BTDC (Before Top Dead Center) (2) 15° BTDC.
(3) 20° BTDC (4) Direction of Rotation.
(5) TDC (Top Dead Center)