Arctic Cat DVX 400 Operator's Manual page 16

Spark plug
The ATV comes equipped with a specified spark plug (see technical data). A light brown
insulator indicates that the plug is correct. A white or dark insulator indicates that the engine
may need to be serviced or the carburetor may need to be adjusted. Take the ATV to an
authorized ACE ATV dealer.
NOTE: If the spark plug fails prematurely due to cold outside temperature, low speed or
low RPM, please contact your Arctic Cat ATV dealer.
Before removing the spark plug, be sure to clean the area around the spark plug. If you do
not, dirt could enter engine when removing or installing the spark plug.
Adjust the gap for proper ignition. Use a feeler gauge to check the gap.
When installing the spark plug, be sure to tighten it securely. A new spark plug should be
tightened ½ turn once the washer contacts the cylinder head. A used plug should be
tightened only 1/8 – ¼ turn.
Engine Idle RPM Adjustment
To properly adjust the idle, a tachometer is necessary. If
one is not available, take the ATV to an authorized ACE
ATV dealer. To adjust idle RPM:
1. Start the engine and warm it up to normal
operating temperature.
2. Turn the throttle stop screw in our out until the
engine idles at the recommended RPM.
Engine Idle RPM : 1250-1350 U/Min
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Adjust the idle to the correct RPM. Make sure the engine is at normal operating temperature
before adjusting the idle RPM.
Throttle Cable Adjustment
To adjust the throttle cable free-play:
1. Loosen the jam nut.
2. Slide the rubber boot away and turn the adjuster
until the throttle lever has proper free-play of 3-6 mm.
3. Tighten the knurled nut against the throttle cable
adjuster securely; then slide the rubber boot over the
adjuster.
Carburetor Float Bowl
Periodically, the float bowl should be drained. Your ACE ATV dealer will do this service.
Gas/Vent Hoses
Replace the gas hose every two years. Do not bend or obstruct the routing of the carburetor
vent hose. Make certain that the vent hose is securely connected to the carburetor and
hose holder and the opposite end is always open.
Air Filter
The air filter inside the air filter housing must
be kept clean to provide good engine power. If
the ATV is used under normal conditions,
service the filter at the intervals specified. If
operated in dusty, wet or muddy conditions,
inspect and service the filter more frequently.
Use the following procedure to remove the
filter and inspect and/or clean it:
!! ATTENTION !!
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