Inspection m e a s u r e m e n t s r e q u i r e a
precision inside and outside micrometer, dial
gauge or the equivalent (Figure 2 and Figure 3).
If you don't have the right tools, remove the
parts and have your dealer or machine shop
take the required measurements.
The unit construction combines the power
plant, clutch and transmission into one set of
The crankcase is the front portion of the
aluminum alloy engine cases, which are split
horizontally. The forged one-piece crankshaft
is mounted in 5 split insert main bearings.
Power is delivered to a secondary shaft by a
primary drive chain inside the crankcase. The
secondary shaft drives the clutch ring gear and
contains the starter clutch mechanism.
The 4 pistons operate inside an alloy
cylinder block with pressed-in iron cylinder
sleeves. The alloy cylinder head houses the
overhead camshafts. Both camshafts are
driven by a single chain from a sprocket on the
crankshaft (between cylinders 2 and 3). The
cam lobes depress lifter cups fitted to the tops
of the valve stems, opening the valves.
The alternator is mounted on the left-hand
end of the crankshaft. The ignition timing
system (contact breaker points or electronic
pickups) and advance mechanism are on the
right-hand end of the crankshaft.
Engine lubrication is by wet sump, with the
oil supply stored in the bottom of the
crankcase. An oil pump, reached from the
bottom of the engine, feeds the main and
big-end bearings, primary chain, camshafts
and valves, and some of the bearings on the
The KZ550-D is factory-equipped with an
Following cylinder repair (boring, honing,
new rings, etc.) and major lower end work, the
engine should be broken in just as though it
were new. The performance and service life of
the engine depend greatly on a careful and
sensible break-in. For the first 500 miles. no
more than 1/3 throttle should be used and
speed should be varied as much as possible
within the 1/3 throttle limit. Avoid prolonged.
steady running at one speed, no matter how
moderate, as well as hard acceleration.
Following a 500 mile service, increasingly
more throttle can be used, but full throttle
should not be used until the motorcycle has
covered at least 1,000 miles and then it should
be limited to short bursts until 1,500 miles
have been logged.
The engine has been laid out so that most top
end repairs (camshaft, cylinder head, cylinder
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