Decompression System; Spark Plug; Crankcase Ventilation System; Fuel Line - Yamaha XT550J Service Manual

B. Decompression System
NOTE: _ _ _ _ _ _ _ _ _ _ _
Decamp-cable adjustment must follow the
valve clearance adjustment.
1. Remove the two blind plugs on the left
crankcase cover.
2. Align the "T" mark on the flywheel with
the timing mark on the crankcase cover.
This places the piston at Top Dead
Center, and the decamp-cable adjust-
ment should be checked and adjusted
with the piston at T.D.C. on the com-
pression stroke.
3. Loosen the locknut on the decomp-
cable adjuster. Then turn the adjuster so
0.5 mm (0.02 in) free play can be provid-
ed for the end of the decomp-Iever.
LOCK NUT ADJUSTER
/
1. Adjuster
2. Lock nut
3. Decomp-Iever
4. After the above adjustment, tighten the
locknut on the decomp-cable adjuster.
5. Reinstall the two blind plugs on the left
crankcase cover.
C. Spark Plug
1. Check electrode condition and wear, in-
sulator color and electrode gap.
2. Clean the spark plug with a spark plug
cleaner if necessary.
Use a wire gauge to adjust the plug gap
to the specification.
3. If the electrodes become too worn,
replace it.
4. When installing the plug, always clean
Standard spark plug: NGK D7EA
Spark plug gap:
0.6 - 0.7 mm (0.024 - 0.028 in)
Spark plug tightening torque:
20 Nm (2.0 m . kg, 14 ft 'Ib)
D. Crankcase Ventilation System
Check ventilation pipe from cylinder head
cover to oil tank and breather assembly from
crankcase to air cleaner for cracks or
damage; replace if necessary.
E. Fuel Line
Check fuel pipe from fuel petcock to car-
buretor for cracks or damage; replace if
necessary.
F. Exhaust System
1. Replace the joint gasket(s) if necessary.
2. Tighten the joint bolt and nuts.
G. Idle Speed
1. Start the engine and warm it up for a
few minutes.
2. Set the engine idle speed to the
specified level by adjusting the throttle
stop screw on the carburetor. Turning
the throttle stop screw in (clockwise)
increases the engine speed; turning
it out (counterclockwise)decreases the
engine speed. Use a tachometer for
checking and adjusting the engine
speed.
Engine Idle: 1,150 - 1,250 r / min
the gasket surface, wipe off any grime
1. Throttle stop screw
that might be present on the surface of
the spark plug, and torque the spark
plug properly.
2-4