Yanmar 1GM User Manual page 16

GENERAL INFORMATI ON
tions. The lower the number, the easier the engine will
turn over in cold climates. Higher numbers arc usually
recommended for engine running in hot weather condi-
tions.
Additional informat ion is provided in Chapter Four.
Grease
Greases are graded by the
National Lubricating Grease
Institute (NLGT). Greases are graded by number accord-
ing to the consistency of the grease; these range fro m No.
000 to No.6, wit h No.6 being the most solid . A typical
multipurpose grease is
NLGI
No .2 . For specific applica-
tions, equipment manufacturers may require grease with
an additive such as molybdenum disulfide (MoS
2 ) .
RTV G ASKET SEALANT
Room temperature vulcanizing (RTV) sealant is used
on some pre-formed gaskets and to seal some compo-
nents. RT V is a silicone gel supplied in tubes and can be
purchased in a number of different colors.
Moisture in the air causes RTV to cure. Always place
the cap on the tube as soon as possible when using RTV
RTV has a she lf life of one year and wi ll not cure properly
if the shelf life has expired . Check the expiration date on
RTV tubes before usc, and keep partially used tubes
tightly sealed.
Applying RTV Seala nt
Clean all gasket residue and contaminants from mating
surfaces. Remove all RTV gasket material from blind at-
taching holes, as it will affect bolt torque.
Apply RTV sealant in a continuous bead 2-3 mm
(0.08-0.12
in.) thick. Circle all mounting holes unless oth-
en-vise specified. Torque mating parts within 10 minutes
after application.
9
Tl IR EA DLOCK
Because of the mar ine engine's opera ting conditions, a
threadlock (F igu re 16) is requ ired to help secure many of
the fasteners. A threadlock will lock fasteners against vi-
bration loose ning and seal against leaks . Loctite 242
(blue) and 27 1 (red) are recommended for many
threadlock requirements described in this manual.
Loctite 242 (blue) is a medium-strength threadlock, and
component disassembly can be performed with normal
hand tools. Loctite 27 1 (red) is a high-strength threadlock,
and heat or special tools, such as a press or puller , arc re-
quired for component disassembly.
Ap plying T hread lock
Surfaces should be clean . If a threadlock was previ-
ously applied to the component, this residue should also
be removed.
Shake the Loctite container thoroughly and apply to
both parts. Assemble parts and/or tighten fasteners.
BASIC llANO TO OL S
Many of the procedures in this manual can accom-
plished with simple hand tools and test equipment famil -
iar to the average home mechan ic. Keep too ls clean and
organized in a toolbox. After using a tool , wipe off dirt
and grease and return the tool to its correct place. Wiping
tools off is especially important if servicing the craft in ar-
eas where they can come in contact with sand. Sand is
very abrasive and will cause premature wear to engine
parts .
High-quality tools are essential; they arc also more eco-
nomica l in the long run. Stay away from the adve rtised
specials featured at some stores . These are usually a poor
grade tool that can be sold cheaply. They are usually made
of inferior material and arc thick, heavy and clumsy. Their
rough finish makes them difficult to clean , and they usu-
ally don't last very long .
Quality tools are made ofalloy steel and arc heat treated
for greater strength. They are lighter and better balanced
than poorly made ones. Their surface is smooth, making
them a pleasure to work with and easy to clean. The initial
cost of quality tools may be more, but they are less expen -
sive in the long run.
The following tools are required to perform virtua lly
any repair job. Each tool is described and the recom-
mended sizes given . Metric size tools arc requ ired to ser-
vice Yanmar diesels.
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