Honda TRX400EX FOURTRAX 1999, Service Manual

Page: 77 / 263

PILOT SCREW ADJUSTMENT
IDLE DROP PROCEDURE
NOTE:
The pilot screw is factory pre-set and no adjustment
is necessary unless the pilot screw
i s
replaced.
Use a tachometer with graduations of
50
rpm or
smaller that w i l l accurately indicate
a 50 r p m
change.
Turn the pilot screw clockwise until it seats lightly,
then back it out to the specification given. This
i s
an initial setting prior to the final pilot screw
adjustment.
CAUTION:
Damage to the pilot screw seat will occur if the pilot
screw is tightened against the seat.
TOOL
Pilot screw wrench 07908-4220201
INITIAL OPENING: 2-1/4 turns out
2.
Warm up the engine to operating temperature.
Stop and go riding for
10 minutes is sufficient.
3. Stop the engine and connect a tachometer accord-
ing to the tachometer manufacturer’s instructions.
4. Start the engine and adjust the idle speed with the
throttle stop screw.
IDLE SPEED: 100
5. Turn the pilot screw in or out slowly to obtain the
6. Lightly open the throttle 2
-
3 times, then adjust
Turn the pilot screw in gradually until the engine
8. Turn the pilot screw out to the final opening.
FINAL OPENING: 1 turn out
9.
Readjust the idle speed with the throttle stop screw.
highest engine speed.
the idle speed with the throttle stop screw.
speed drops by 50 rpm.
SCREW STOP SCREW
5-1
3