CHAPTER TWO
TROUBLESHOOTING
Begin any troubleshooting procedure by defining
the symptoms as precisely as possible. Gather as
much information as possible to aid diagnosis.
Never assume anything and do not overlook the ob-
vious. Make sure there is fuel in the tank, and the
fuel valve is in the on position. Make sure the en-
gine stop switch is in the run position and the spark
plug wires are attached to the spark plugs.
If a quick check does not reveal the problem, turn
to the troubleshooting procedures described in this
chapter. Identify the procedure that most closely de-
scribes the symptoms, and perform the indicated
tests.
In most cases, expensive and complicated test
equipment is not needed to determine whether re-
pairs can be performed at home. A few simple
checks could prevent an unnecessary repair charge.
On the other hand, be realistic and do not attempt
repairs beyond your capabilities. Many service de-
partments will not take work that involves the reas-
sembly of damaged or abused equipment. If they
do, expect the cost to be high.
OPERATING REQUIREMENTS
An engine needs three basic requirements to run
properly: correct air/fuel mixture, compression and
a spark at the proper time. If any element is missing,
the engine will not run. Four-stroke engine operat-
ing principles are described in
Figure 1
.
If the machine has been sitting for any length of
time and refuses to start, check and clean the spark
plugs and then look to the fuel delivery system. This
includes the fuel tank, fuel valve, fuel pump and
fuel lines to the carburetor. Gasoline deposits may
have gummed up the carburetor jets and air pas-
sages.
Gasoline tends to lose its potency after standing
for long periods. Condensation may contaminate
the fuel with water. Drain the old fuel (fuel tank,
fuel lines and carburetor) and try starting with a
tank of fresh gasoline.
STARTING THE ENGINE
Starting Preliminaries
1. A sidestand ignition cutoff system is used. The
position of the sidestand affects engine starting.
Note the following:
a. The engine cannot start when the sidestand is
down and the transmission is in gear.
b. The engine can start when the sidestand is
down and the transmission is in neutral. The
engine will stop, however, if the transmission
is put in gear while the sidestand is down.