Yamaha YFM 90, Owner'S Manual

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8
TIP
The engine is warm when it quickly responds to
the throttle.
2. Attach the tachometer to the spark plug lead.
3. Check the engine idling speed and, if neces-
sary, adjust it to specification by turning the
throttle stop screw at the carburetor. To in-
crease the engine idling speed, turn the throt-
tle stop screw in direction (a), and to decrease
it, turn the screw in direction (b).
TIP
If the specified idling speed cannot be obtained as
described above, have a Yamaha dealer make the
adjustment.
EBU33950
Adjusting the throttle lever free play
The throttle lever free play should be checked and,
if necessary, adjusted at the intervals specified in
the periodic maintenance and lubrication chart.
The throttle lever free play should measure 1.5–4.0
mm (0.06–0.16 in) as shown. Periodically check
the throttle lever free play and, if necessary, adjust
it as follows.
TIP
The engine idling speed must be checked, and
adjusted if necessary, before adjusting the throttle
lever free play.
1. Slide the rubber covers apart.
2. Loosen the locknut.
3. To increase the throttle lever free play, turn
the throttle lever free play adjusting nut in di-
rection (a). To decrease the throttle lever free
play, turn the adjusting nut in direction (b).
1. Throttle stop screw
Engine idling speed:
1600–1800 r/min
(a)
(b)
1
UBD362E0.book Page 20 Tuesday, January 31, 2017 5:10 PM