Yanmar 6LY3 series - TROUBLESHOOTING CHART

ENGINE
Inspecting the Cylinder Block and Components
5-50 6LY3 Service Manual
© 2007 Yanmar Marine International
Inspecting the Tappets
The tappets are offset (Figure 5-68, (1)) to rotate
during operation and prevent uneven wear.
Figure 5-68
Figure 5-68
1 – Offset
Figure 5-69
Figure 5-69
1–Notches
NOTICE: When removing tappets, keep them
separate from each cylinder. The exhaust valve
tappet side has two notches (Figure 5-69, (1)) on
the top of the tappet. The tappet for the intake valve
has no notch.
• Check the contact area of each tappet.
• Replace if excessively or unevenly worn.
Figure 5-70
Figure 5-70
1 – Abnormal Contact Area
2 – Normal Contact Area
• Measure the outer diameter of the tappet
(Figure 5-71).
• Replace if worn beyond the stated limits.
Figure 5-71
Figure 5-71
0005654
(1) (1)
0005655
(1)
0005653
(1) (2)
Tappet Specifications
Standard Limit
Tappet Stem Outside
Diameter
14.218-14.233 mm
(0.5597-0.5603 in.)
14.17 mm
(0.5578 in.)
Tappet Guide Hole
Inside Diameter
(cylinder block)
14.249-14.270 mm
(0.5609 -0.5618 in.)
14.30 mm
(0.5629 in.)
Oil Clearance
0.016-0.052 mm
(0.0006-0.0020 in.)
0.10 mm
(0.0039 in.)
0005656