GENERAL INFORMATION
33
739-152G
At high RPM, the exhaust valves are
raised. This creates a “high port”
exhaust design calibrated to provide
maximum performance at high RPM.
739-152H
NOTE: The RPM ranges will vary
from model to model.
NOTE: If the servomotor cycles
three times and then shuts down,
the exhaust valve cables are not
adjusted correctly. The exhaust
valves may also be sticking.
NOTE: APV cleaning may be
done by the snowmobile owner if
qualified to do so. If the owner
does not feel qualified, take the
snowmobile to an authorized Arc-
tic Cat Snowmobile dealer for this
service. This service is at the dis-
cretion and expense of the snow-
mobile owner.
EXHAUST
CONTROLLED TIMING
(ECT) SYSTEM (600/
800/1000 cc Models)
This system automatically adjusts the
ignition timing to provide maximum
performance through a variety of
operating conditions. The ECU
receives input on engine RPM
(demand) and exhaust pipe tempera-
ture (engine condition) and adjusts the
ignition timing accordingly. This sys-
tem is not adjustable and is mainte-
nance free.
If a system fault is suspected, use an
ohmmeter to check continuity of the
exhaust pipe temperature sensor
located in the expansion chamber. A
reading of either 0 ohm or infinity
indicates a failed sensor.
0737-314
NOTE: A disabled ECT system
WILL NOT cause engine damage;
however, a failed ECT system will
have slower throttle response and
may produce slightly less top-end
performance.
