Yamaha WR45OFR service manual Pilot system, Main jet adjustment, Standard main jet #150 #160

SETTING

T U N

Pilot system

The FLATCR carburetor is manufactured with a pilot screw. The pilot screw adjustment ranges from fully closed throttle to 1/4 open throttle.

Main jet adjustment

The richness of the air-fuel mixture at full throt- tle can be set by changing the main jet 1.

Standard main jet

#150

*#160

* Except for USA

If the air-fuel mixture is too rich or too lean, the engine power will drop, resulting in poor accel- eration.

Effects of changing the main jet (reference)

Å 1/4 1/2 3/4

#160

#140

ı

+10%

#150

–10%

ÅIdle ı Fully open

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