Yamaha WaveRunner VX 700 Service Manual page 174

TRBL
SHTG
Symptom 2
Fuel not supplied (all
cylinders)
Compression pres-
sure is low
Symptom 1: Unstable engine idle speed, poor acceleration, poor performance, or limited
engine speed
Symptom 2
Throttle valve does
not move properly
Spark plug does not
spark (some cylin-
ders)
Fuel not supplied
(some cylinders)
9-3
Troubleshooting
Cause
Fuel leakage
Clogged fuel filter
Fuel pump malfunction
Improper low speed screw
setting
Air-fuel mixture not sup-
plied
Compression leakage
Cause
Throttle cable installed
incorrectly
Throttle valve malfunction
Improper throttle stop
screw setting
Spark plug malfunction
Ignition coil malfunction
Short, open, or loose con-
nection in ignition coil cir-
cuit
Improper low speed screw
setting
Improper high speed
screw setting
Air-fuel mixture not sup-
plied
Checking step
Check the fuel hose.
Replace the fuel filter.
Check the fuel pump onto the car-
buretor.
Adjust the low speed screw.
Check the reed valve.
Measure the compression pres-
sure.
Check the cylinder head gasket
and cylinder head warpage.
Check the piston and piston ring for
damage.
Check the cylinder for damage.
Checking step
Adjust the throttle lever free play.
Check the throttle valve synchroni-
zation.
Adjust the throttle stop screw.
Check the spark plug.
Check the ignition spark.
Measure the ignition coil resis-
tance.
Check the ignition coil wiring har-
ness leads for continuity.
Adjust the low speed screw.
Adjust the high speed screw.
Check the reed valve.
See
page
3-3
3-3
4-14
4-15
5-15
3-5
5-17
5-22
5-19
See
page
3-2
4-15
3-6
3-4
7-5
7-6
WD
4-15
4-15
5-15