Yanmar 4LHA-STP User Manual

Chapter 2 Basic Engine
6. Connecting Rod
M4LHA Seri.
6-3 Piston pin bushing
(1) Measuring piston pin clearanoe
Excessive piston pin bushing wear may result damage to
the piston pin or the piston itself.
6-4 Assembling piston and connecting rod
The piston and connecting rod should be assembled so that
the match mamk on the connecting nod large end faces the
fuel injection pump side and the combustion chamber above
the piston is close to the fuel injection pump.
Cylinder gauge
Gear case side
Fuel injection pump
Piston size mark
mm(in.)
Piston
All
Standard
Wear limit
Piston pin bushing
inside dia
37.03-37.05
(1.4579-1.4587)
37.10
(1.4606)
Piston pin and bushing
oil clearance
0.030-0.061
(0.0012-0.0024)
(2) Replacing piston pin bushing
1)When the bushing for the connecting rod piston pin is ei-
ther worn out or damaged, replace it by using the "piston
pin extracting tool" installed on a press.
Flywheel
Alignment marl
NOTE: Force the piston pin bushing into position so that its
oil hole coincides with the hole on the small end of the
connecting rod.
2-27

Yanmar 4LHA-STP Specifications

General

Number of Cylinders	4
Fuel System	Direct Injection
Engine Type	4-Stroke Vertical Water-Cooled Diesel Engine
Displacement	3.455 L
Bore x Stroke	100 mm x 110 mm
Aspiration	Turbocharged