9/26/2017
Service Manual Model J
http://www.sky-net.org.uk/kelvin/diesel/j_range/man/index.html
12/17
73. VALVES INCLINED TO STICK.--Should a valve stick, the piston will strike it.
The oil well on top of each cylinder lubricates the rockers. The surplus lubricates the
valve stems. Should a joint between the top of the cylinder and the rocker block
become broken or charred, the oil intended for the valve stems might escape.
74. PISTON.--The piston and connecting rod are removable through the inspection
door on the starboard side. It is desirable to have some assistance to turn the flywheel,
in order to bring the crank into the various positions necessary for this operation. If
any of the piston rings are stuck fast, they must be broken out and renewed.
75. PISTON RINGS.--If the slackness sideways exceeds .020", the, grooves should
be enlarged for oversize (.030"). rings. If the pistons cannot be sent to us for this
service, it must be done locally. A small piece of a new ring will be found useful as a
gauge. The groove should be of sufficient width to allow it to enter flush, along with a
feeler .004" to provide, the necessary clearance.
76. EXCESSIVE OIL CONSUMPTION.--This may be due to the use of oil which
loses its viscosity when hot
; if the consumption has, gradually increased it is
probably due to the piston rings having become slack in their grooves; ring groove
wear is, in turn, due to cylinder wear, and cylinder wear, according to the latest
opinions, is due partly to high gas pressure and partly to corrosion resulting from
combustion. It is thought that most of the wear occurs before the cylinder liner has
heated up, during which time the products of combustion condense on the liner and
corrode it. It is therefore important to heat up the cylinder quickly and maintain the
temperature of it as near boiling point as possible. The practice of starting a cold
engine long before it can be put on load causes cylinder wear.
77. EXHAUST MANIFOLD.--If the manifold, appears to become hotter remove the
end covers and scrape out any salt accumulated. As the joints are perishable, it is
necessary to have spares at hand.
*78 FLYWHEEL.--The attachment of the flywheel is important. If it is necessary to
remove it, draw the bolts by means of the puller and stud in the tool box. These bolts
must be oiled and replaced with care as a loose flywheel may involve a new
crankshaft.
79. TIMING GEARS.--These are within the case behind the flywheel. They are all
marked to indicate how they must be assembled. It is possible to see the gears without
removing the flywheel. First remove the flywheel pan, then slacken the cover.
80. FIRING ORDER.
Firing order
J2
J3
J4
Rotation clock-wise
1002
132
1243
Rotation anti-clock-wise
1002
123
1243
81. OIL ESCAPES BEHIND FLYWHEEL.--If water is permitted to reach the
crankshaft at the back of the flywheel, rust will occur, and the white metal oil
