Service manual

ManualsBrandsYamaha ManualsEngine2009 Wave Runner VX

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TRBL

SHTG

Troubleshooting

9-3

Symptom 1: Unstable engine idle speed, poor acceleration, poor performance, or limited

engine speed

Fuel not supplied (all

cylinders)

Fuel leakage Check the fuel hose. 3-3

Clogged fuel filter Replace the fuel filter. 3-3

Fuel pump malfunction Check the fuel pump onto the car-

buretor.

4-14

Improper low speed screw

setting

Adjust the low speed screw. 4-15

Air-fuel mixture not sup-

plied

Check the reed valve. 5-15

Compression pres-

sure is low

Compression leakage Measure the compression pres-

sure.

3-5

Check the cylinder head gasket

and cylinder head warpage.

5-17

Check the piston and piston ring for

damage.

5-22

Check the cylinder for damage. 5-19

Symptom 2 Cause Checking step

See

page

Throttle valve does

not move properly

Throttle cable installed

incorrectly

Adjust the throttle lever free play. 3-2

Throttle valve malfunction Check the throttle valve synchroni-

zation.

4-15

Improper throttle stop

screw setting

Adjust the throttle stop screw. 3-6

Spark plug does not

spark (some cylin-

ders)

Spark plug malfunction Check the spark plug. 3-4

Ignition coil malfunction Check the ignition spark. 7-5

Short, open, or loose con-

nection in ignition coil cir-

cuit

Measure the ignition coil resis-

tance.

7-6

Check the ignition coil wiring har-

ness leads for continuity.

Fuel not supplied

(some cylinders)