Chapter 1
clutch and gearbox
19
... rear mounting nuts to release complete exhaust system 5.7 Release the locking plate to permit sprocket removal
5.8a Disconnect the battery to isolate the electrical system
6 Dismantling the engine and gearbox unit: general
1 Before commencing work on the engine unit, the external
surfaces should be cleaned thoroughly. A motor cycle engine
has very little protection from road grit and other foreign matter,
which will find its way into the dismantled engine if this simple
precaution is not taken. One of the proprietary cleaning com-
pounds, such as 'Gunk' or 'Jizer' can be used to good effect,
particularly if the compound is permitted to work into the film of
oil and grease before it is washed away. Special care is
necessary, when washing down to prevent water from entering
the now exposed parts of the engine unit.
2 Never use undue force to remove any stubborn part unless
specific mention is made of this requirement. There is invariably
good reason why a part is difficult to remove, often because the
dismantling operation has been tackled in the wrong sequence.
3 Mention has already been made of the benefits of owning
an impact driver. Most of these tools are equipped with a
standard inch drive and an adaptor which can take a variety of
screwdriver bits. It will be found that most engine casing screws
will need jarring free due to both the effects of assembly by
power tools and an inherent tendency for screws to become
pinched in alloy castings.
4 A cursory glance over many machines of only a few years
5.8b ... then separate the generator output lead connector
use, will almost invariably reveal an array of well-chewed screw
heads. Not only is this unsightly, it can also make emergency
repairs impossible. It should also be borne in mind that there are
a number of types of crosshead screwdrivers which differ in the
angle and design of the driving tangs. To this end, it is always
advisable to ensure that the correct tool is available to suit a
particular screw.
5 In addition to the above points, it is worth noting before any
dismantling work is undertaken that it is desirable to have two
service tools available. The first, and most important, is a
flywheel puller, Honda part number
or a
cheaper pattern version, and secondly, a special peg spanner for
releasing the centrifugal oil filter housing, Honda part number
The latter can be fabricated from a piece of
tubing, if necessary, but it is much less easy to make do without
the flywheel extractor as the flywheel proved to be a very tight
fit.
7 Dismantling the engine and gearbox unit: removing the
cylinder
barrel and piston
1 If the cylinder head is to be removed with the engine unit in
the frame, start by removing the carburettor and heat shield, the
