0-11
Maintenance techniques,
tools and working facilities
Basic maintenance techniques
There are a number of techniques involved in maintenance and
repair that will be referred to throughout this manual. Application of
these techniques will enable the amateur mechanic to be more
efficient, better organized and capable of performing the various tasks
properly, which will ensure that the repair job is thorough and
complete.
Fastening systems
Fasteners, basically, are nuts, bolts and screws used to hold two
or more parts together. There are a few things to keep in mind when
working with fasteners. Almost all of them use a locking device of
some type (either a lock washer, locknut, locking tab or thread
adhesive). All threaded fasteners should be clean, straight, have
undamaged threads and undamaged corners on the hex head where
the wrench fits. Develop the habit of replacing all damaged nuts and
bolts with new ones.
Rusted nuts and bolts should be treated with a penetrating oil to
ease removal and prevent breakage. Some mechanics use turpentine
in a spout type oil can, which works quite well. After applying the rust
penetrant, let it "work" for a few minutes before trying to loosen the nut
or bolt. Badly rusted fasteners may have to be chiseled off or removed
with a special nut breaker, available at tool stores.
If a bolt or stud breaks off in an assembly, it can be drilled out and
removed with a special tool called an E-Z out (or screw extractor).
Most dealer service departments and motorcycle repair shops can
perform this task, as well as others (such as the repair of threaded
holes that have been stripped out).
Flat washers and lock washers, when removed from an assembly,
should always be replaced exactly as removed. Replace any damaged
washers with new ones. Always use a flat washer between a lock
washer and any soft metal surface (such as aluminum), thin sheet
metal or plastic. Special locknuts can only be used once or twice
before they lose their locking ability and must be replaced.
Tightening sequences and procedures
When threaded fasteners are tightened, they are often tightened
to a specific torque value (torque is basically a twisting force). Over-
tightening the fastener can weaken it and cause it to break, while
under-tightening can cause it to eventually come loose. Each bolt,
depending on the material it's made of, the diameter of its shank and
the material it is threaded into, has a specific torque value, which is
noted in the Specifications. Be sure to follow the torque recommen-
dations closely.
Fasteners laid out in a pattern (i.e. cylinder head bolts, engine
case bolts, etc.) must be loosened or tightened in a sequence to avoid
warping the component. Initially, the bolts/nuts should go on finger
tight only. Next, they should be tightened one full turn each, in a criss-
cross or diagonal pattern. After each one has been tightened one full
turn, return to the first one tightened and tighten them all one half turn,
following the same pattern. Finally, tighten each of them one quarter
turn at a time until each fastener has been tightened to the proper
torque. To loosen and remove the fasteners the procedure would be
reversed.
Disassembly sequence
Component disassembly should be done with care and purpose
to help ensure that the parts go back together properly during
reassembly. Always keep track of the sequence in which parts are
removed. Take note of special characteristics or marks on parts that
can be installed more than one way (such as a grooved thrust washer
on a shaft). It's a good idea to lay the disassembled parts out on a
clean surface in the order that they were removed. It may also be
helpful to make sketches or take instant photos of components before
removal.
When removing fasteners from a component, keep track of their
locations. Sometimes threading a bolt back in a part, or putting the
washers and nut back on a stud, can prevent mixups later. If nuts and
bolts can't be returned to their original locations, they should be kept in
a compartmented box or a series of small boxes. A cupcake or muffin
tin is ideal for this purpose, since each cavity can hold the bolts and
nuts from a particular area (i.e. engine case bolts, valve cover bolts,
engine mount bolts, etc.). A pan of this type is especially helpful when
working on assemblies with very small parts (such as the carburetors
and the valve train). The cavities can be marked with paint or tape to
identify the contents.
Whenever wiring looms, harnesses or connectors are separated,
it's a good idea to identify the two halves with numbered pieces of
masking tape so they can be easily reconnected.
Gasket sealing surfaces
Throughout any motorcycle, gaskets are used to seal the mating
surfaces between components and keep lubricants, fluids, vacuum or
pressure contained in an assembly.
Many times these gaskets are coated with a liquid or paste type
gasket sealing compound before assembly. Age, heat and pressure
can sometimes cause the two parts to stick together so tightly that
they are very difficult to separate. In most cases, the part can be
loosened by striking it with a soft-faced hammer near the mating
surfaces. A regular hammer can be used if a block of wood is placed
between the hammer and the part. Do not hammer on cast parts or
parts that could be easily damaged. With any particularly stubborn
part, always recheck to make sure that every fastener has been
removed.
Avoid using a screwdriver or bar to pry apart components, as they
can easily mar the gasket Sealing surfaces of the parts (which must
remain smooth). If prying is absolutely necessary, use a piece of wood,
but keep in mind that extra clean-up will be necessary if the wood
splinters.
After the parts are separated, the old gasket must be carefully
scraped off and the gasket surfaces cleaned. Stubborn gasket material
can be soaked with a gasket remover (available in aerosol cans) to
soften it so it can be easily scraped off. A scraper can be fashioned
from a piece of copper tubing by flattening and sharpening one end.
Copper is recommended because it is usually softer than the surfaces
to be scraped, which reduces the chance of gouging the part. Some
gaskets can be removed with a wire brush, but regardless of the
method used, the mating surfaces must be left clean and smooth. If for
some reason the gasket surface is gouged, then a gasket sealer thick
enough to fill scratches will have to be used during reassembly of the
components. For most applications, a non-drying (or semi-drying)
gasket sealer is best.
Hose removal tips
Hose removal precautions closely parallel gasket removal
precautions. Avoid scratching or gouging the surface that the hose
mates against or the connection may leak. Because of various
chemical reactions, the rubber in hoses can bond itself to the metal
spigot that the hose fits over. To remove a hose, first loosen the hose
clamps that secure it to the spigot. Then, with slip joint pliers, grab the
hose at the clamp and rotate it around the spigot. Work it back and
forth until it is completely free, then pull it off (silicone or other
lubricants will ease removal if they can be applied between the hose
and the outside of the spigot). Apply the same lubricant to the inside of
the hose and the outside of the spigot to simplify installation.
