Troubleshooting Guide - Yamaha DT125LC Wartungsanleitung

CHAPTER
8.
APPENDICES
TROUBLESHOOTING GUIDE
The
following
guide is not complete in itself . lf a problem
is
found within
an individual component mentioned in the chart, refer to the section or
chapter involved for inspection procedures.
1.
Will not start or difficult to start
a.
lgnition system
2.
Poor idle and/or low
speed performance
a.
lgnition system
c.
Engine/ Exhaust systems
Possible cause Remedy
lncorrect compression pressure 1.
lf compression
is
too high, check
for excessive carbon buildup.
2.
No
compression or low compression,
check:
a.
Cylinderhead
gasket.
b.
Cylinder base gasket.
c.
Piston, rings, cylinder.
Poor
bottom
end compression
Check
crankcase
seals.
Blocked exhaust
system
1.
Check
muffler/spark
arrester.
2.
Check
exhaust port carbon
formation.
3.
Check exhaust
pipe
for internal
damage.
Possible cause Remedy
No spark
1.
2.
3.
4.
5.
6.
7.
8.
Check
ignition main switch.
Check
pick-up coil.
Check
charging coil.
Check
wiring, magneto coil.
Check ignition coil.
Check high tension lead.
Check spark
plug.
Check
ignition
timing.
Weak or
intermittent
spark
1
.
Use Electro
Tester, spark gap test.
2.
Check spark
plug.
3.
Check
high tension lead.
4.
Check
ignition
assembly.
Possible cause Remedy
Spark
plug fouled
or
incorrect gap
Clean and
gap. or replace if necessary.
lncorrect ignition timing
Reset
timing.
Weak
spark Check
ignition coil
and condenser.
b.
Ar/Fuelsystems
Possible cause
Remedy
No
fuel
1.
Checkfueltank.
2.
Check
petcock.
3.
Remove
fuel pipe,
check fuel
flow.
lntermittent or poor fuel flow 'l
.
Clean
fuel tank,
check cap
vent.
2.
Clean
petcock.
3.
Remove carburetor, service.
Bad
fuel
1.
2.
Flush
fuel system, complete.
Add fresh fuel, proper grade.
Blocked air
intake or malfunction
1.
Clean
and
lube filter.
2.
Check reed valve assembly.
b. Air/
Fuel systems
Possible cause Remedy
Tank cap
vent plugged
Clean or repair
as
necessary.
Fuel
petcock plugged
Clean
or
repair
as
necessary.
Carburetor slow speed system
inoperative
Clean or repair
as
necessary.
Pilot
screw out of adjustment or plugged
Adjust or clean
as
necessary.
Carburetor float
level
incorrect
Measure and adjust
as
required.
Starter lever on Push lever
off.
Air leak
Repair.
Carburetor not
level Level.
8-1