Yanmar 1GM10 Shop Manual Download

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CHAPTER ONE

to make alignment. Insert a new cotter pin through the nut
and hole, then tap the head lightly to seat it. Bend one arm
over the flat on the nut and the other against the top of the

stud or bolt (Figure 13).

the arms to a suitable length

to prevent them from snagging on clothing or skin. When
the cotter pin is bent and its arms cut to length, it should be
tight. If it can be wiggled, it is improperly installed.

Do not reuse cotter pins, as their ends may break and al-

low the cotter pin to fall out and the fastener to loosen.

Circlips

Circlips can be internal or external design. They are

used to retain items on shafts (external type) or within
tubes (internal type). In some applications, circlips of

varying thickness are used to control the end play of parts
assemblies. These are often called selective circlips. Re-
place circlips during installation, as removal weakens and
deforms them.

Two basic styles of circlips are available: machined and

stamped circlips. Machined circlips (Figure 14) can be in-
stalled in either direction (shaft or housing) because both
faces are machined, thus creating two sharp edges.
Stamped circlips (Figure 15) are manufactured with one
sharp edge and one rounded edge. When installing
stamped circlips in a thrust situation, the sharp edge must
face away from the part producing the thrust. When in-
stalling circlips, observe the following:

a. Remove and install circlips with circlip pliers. See

Circlip Pliers

in this chapter.

b. Compress or expand circlips only enough to install

them.

c. After the circlip is installed, make sure it is com-

pletely seated in its groove.

LUBRICANTS

Periodic lubrication ensures long life for any type of

equipment. The type of lubricant used  is as important as
the  lubrication service  itself, although in  an  emergency
the wrong type of lubricant is better than none at all. The
following  paragraphs  describe  the  types  of  lubricants

most often required. Be sure to follow the manufacturer's
recommendations for lubricant types.

Generally, all liquid lubricants are called oil. They may

be mineral-based (including petroleum bases),
ral-based (vegetable and animal bases), synthetic-based

or emulsions (mixtures). Grease is an oil to which a thick-
ening base has been added so that theoend product is
semi-solid. Grease is often classified by the type of thick-
ener added; lithium soap is commonly used.

support

areas

Rounded edges

edges

Direction of thrust

Engine Oil

Oil for marine and automotive four-stroke engines is

classified by the American Petroleum Institute (API) and
the Society of Automotive Engineers (SAE) in several
categories. Oil containers display these classifications on
the top or label. API oil classification is indicated by let-
ters; oils for gasoline engines are identified by an "S" and
oils for diesel engines are identified by a "C".

Viscosity is an indication of the oil's thickness. The

SAE uses numbers to indicate viscosity; thin oils have low
numbers while thick oils have high numbers. A "W" after
the number indicates that the viscosity testing was done at
low temperature to simulate cold-weather operation. En-
gine oils fall into the 5W-30 and 20W-50 range.

Multi-grade oils (for example

are less viscous

(thinner) at low temperatures and more viscous (thicker)
at high temperatures. This allows the oil to perform
ciently across a wide range of engine operating