Yanmar 1GM User Manual page 23

16
Magnetic Stand
A magnetic stand (F tgu re
af) is used to hold a dial indi-
cator securely when checking the runout of a round object
or when checking the end play of a shaft.
V-bloc ks
V-blocks (Fi gure 42) are precision-ground blocks use d
to ho ld a round object when checking its runout or condi-
tion.
Surface Plate
A surface plate can be used to check the flatness ofparts
or to provide a perfectly fla t surface for minor resurfacing
of cylinder head or other critical gasket surfaces . While
industrial quality surface plates are quite expensive, the
home mechanic can improvise. A thick metal pla te can be
used as a surface plate. The surface plate shown in Fi gu re
43 has a piece ofsandpaper glued to its surface that is used
for cleaning and smoothing machined surfaces, such as
the cylinder head.
NOTE
A local machine shop can fabricate a sur-
face plate.
Expendable Sup plies
Certain expendable supplies are also required. These
include grease , oil, gasket cement, shop rags and cleaning
solvent. Ask the dealer for the special locking com-
pounds, silicone lubricants and lubricants that make vehi-
cle maintenance simpler and easier.
WARNING
Having a stack ofclean shop rags on hand is
important when performing engine work.
However; to prevent the possibility offire,
store solvent-soaked rags in a sealed metal
container until they can be washed or dis-
carded.
NOTE
To avoid absorbing solvent and othe r chem-
icals into the skin while cleaning parts,
wear a pair
of
petroleum-resistant rubber
gloves. These can he purchased through in-
dustrial supply houses or well-equipped
hardware stores.
CHAPTER ONE
1\1ECHANIC'S
TIPS
Removing Frozen Nuts and Screws
When a fastener rusts and cannot be removed, several
methods may be used to loosen it. First, apply penetrat ing
oil such as Liquid Wrench or WD-40. Apply it liberally
and let it penetrate for 10-15 minutes. Rap .thc fastener
several times with a small hammer; do not hit it hard
enough to cause damage. Reapply the penetrat ing oil if
necessary.
For frozen screws, apply penetrating oil as described,
then insert a screwdriv er in the slot and rap the top of the
screwdriver with a hammer. This loosens the rust so the
screw can be removed in the normal way. If the screw
head is too damaged to use this method, grip the head with
locking pliers and twist the screw out.
Avoid applying heat unless specifically instructed, as it
may melt, warp or remove the temper from parts.
Removing Broken Screws or Bolts
lf thc head breaks off a screw or bolt, several methods
arc available for removing the remain ing portion.