Adjusting The Carburetor; Adjusting The Engine Idling Speed - Yamaha BIG BEAR 250 YFM25BZ Owner's Manual

EWB02340
WARNING
Do not start the engine when cleaning the
spark arrester, otherwise it could cause injury
to the eyes, burns, carbon monoxide poison-
ing, possibly leading to death, and start a fire.
Always let the exhaust system cool prior to
touching exhaust components.
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,
8
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.
ECB00480
NOTICE
The carburetor has been set and extensively
tested at the Yamaha factory. Changing these
settings without sufficient technical knowl-
edge may result in poor performance of or
damage to the engine.
EBU24000

Adjusting the engine idling speed

The engine idling speed must be checked and, if
necessary, adjusted as follows at the intervals
specified in the periodic maintenance and lubrica-
tion chart.
TIP
A diagnostic tachometer is needed to make this
adjustment.
1. Start the engine and warm it up.
TIP
The engine is warm when it quickly responds to the
throttle.
2. Attach the tachometer to the spark plug lead.
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