Yamaha YZ85LW Fahrer- Und Wartungshandbuch Seite 475

Symptom
Closed to 1/4 throttle
Poor acceleration
White smoke
Unstable at low speeds
Pinking noise
Poor response at
extremely low speed
Poor response in the low
to intermediate speeds
Poor response when
throttle is opened quickly
Poor engine operation
* marked: In case of hard breathing, check the carburetor breather hoses for clogging.
Setting
Use jet needle with a larger diam-
eter.
Turn in pilot air screw.
Lower jet needle clip position.
(1 groove down)
Turn in pilot air screw.
Reduce pilot jet calibration No.
Turn out pilot air screw.
If not effect, reverse the above
procedures.
Raise jet needle clip position.
If this has no effect, lower the jet
needle clip position.
Check overall settings.
Use main jet with a lower calibra-
tion no.
Raise jet needle clip position.
Use jet needle with a larger diam-
eter.
If these have no effect, use a main
jet with a higher calibration no.
and lower the jet needle clip posi-
tion.
Turn in pilot air screw.
Adjust the throttle stop screw.
7 - 8
SETTING
Dragging brake
Overflow from carburetor
Check air filter for fouling.
Check throttle valve operation.
This should be taken simply for an example. It
is necessary to set the carburetor while check-
ing the operating conditions of the engine and
discoloration of spark plugs.
Normally, carburetor setting is made by means
of the main jet, jet needle clip position, pilot jet
and pilot air screw.
T U N
Checking