Adjusting The Carburetor - Yamaha BIG BEAR 400 Owner's Manual

2. Start the engine and rev it up approximately
twenty times while momentarily creating ex-
haust system back pressure by blocking the
end of the muffler with a shop towel.
3. Stop the engine and allow the exhaust pipe to
cool.
4. Install the purging bolt, and then tighten it to
the specified torque.
Tightening torque:
Purging bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
EWB01920
POTENTIAL HAZARD
8
Improperly purging the exhaust system.
Hot exhaust system.
WHAT CAN HAPPEN
Could injure the eyes.
Could cause burns.
Could cause carbon monoxide poisoning,
possibly leading to death.
Could start a fire.
WARNING
HOW TO AVOID THE HAZARD
When cleaning the spark arrester:
Always let the exhaust system cool prior to
touching exhaust components.
Always wear eye protection, and make sure
no one is behind the ATV.
Never run the engine in an enclosed area.
Make sure there are no combustible materi-
als in the area.
EBU23940

Adjusting the carburetor

The carburetor should be checked and, if neces-
sary, adjusted at the intervals specified in the peri-
odic maintenance and lubrication chart. The
carburetor is an important part of the engine and
requires very sophisticated adjustment. Therefore,
most carburetor adjustments should be left to a
Yamaha dealer, who has the necessary profes-
sional knowledge and experience. The adjustment
described in the following section, however, may
be performed by the owner as part of routine main-
tenance.
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