Ignition Timing (Air-Cooled Engines) - Arctic Cat Cougar Service Manual

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correct mark, perform the Dynamic Timing
Check
as outlined in this chapter.
If the timing is not correct at the engine speed
listed in Table 9, refer to Chapter Two and test
the resistance of the ignition timing sensor (Fig-
ure 68 or Figure 69). If the resistance is incor-
rect, install a new sensor and recheck the timing.
Other problems that may cause the timing to be
incorrect are a damaged flywheel, damaged
drive key or faulty electrical connections.
Ignition Timing (Air-Cooled Engines)
A capacitor discharge ignition (CDI) is used
on 431 cc air-cooled engines. The system is not
usually susceptible to failures caused by dirt,
moisture and wear. It is important to use the
correct procedure when servicing the engine.
Static timing to verify the flywheel timing
marks may be necessary before using a timing
light to check ignition timing. Most flywheels
are marked with several lines, but the correct
timing mark may not be easily distinguished
from the other lines. The static timing procedure
can be used for the following:
a. to verify and identify the factory timing
marks.
b. to detect a broken or missing flywheel Woo-
druff key.
c. to detect a twisted crankshaft.
d. to scribe timing marks on a new flywheel.
NOTE
The ignition timing marks located on the
engine flywheel of air-cooled engines
may be very difficult to view with the
engine installed. A wire, or similar,
pointer can be securely attached to the
engine near the drive pulley, then a tem-
porary timing mark can be scribed on
the pulley for checking the timing with
the engine running. Use the following
static timing check to locate the crank-
shaft at the correct timing position, then
scribe the temporary mark on the sta-
tionary pulley in line with the pointer.
CHAPTER THREE
Dynamic engine timing uses a timing light
connected to the MAG (magneto) side spark plug
lead. As the engine is cranked or running, the
light flashes each time the spark plug fires. When
the light is pointed at the moving flywheel, the
mark on the flywheel appears to stand still. The
flywheel mark should align with the stationary
timing pointer on the engine.
Static timing check
The static timing is only used to locate the
proper position for the ignition timing when the
engine is running at a specific speed. It is impor-
tant to check the ignition timing using the correct
mark and at the engine speed listed in Table 9.
1. Open the hood.
2. Remove all the spark plugs as described in
this chapter.
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