Failure To Start/Difficulties In Starting; Fuel System - Yamaha SZR 660 Service Manual

FAILURE
TO
START/
DIFFICULTIES
IN
STARTING
FAILURE TO
START/
DIFFICULTIES
IN
STARTING
TROUBLESHOOTING
ELECTRICAL
SYSTEM
—
Spark plug
—
NOTE:
,
„
,
„
—
_™™___
The
troubleshooting tables that follow
do not identify every cause of trouble.
They
may
however prove
helpful
as
a
guide to identify trouble.
To
inspect, adjust or
replace
parts, refer to the
appropriate section
in the
manual.
FAILURE
TO START/DIFFICULTIES
IN
STARTING
FUEL
SYSTEM
—
Fuel tank
Fuel tap
n
PROBABLE CAUSES
• Empty
•
Fuel
litter
obstructed
•
Fuel tank
air
cap passage
obstructed
•
Petrol
contains water
or impurities or
is
adu
Iterated
Hose
obstructed
Carburetor
Air lifter
Fuel
pump
ignition
coil
Ignition unit
Fuel
filter
obstructed
Petrol contains
water
or impurities
or
is
adulterated
Pilot
jet
obstructed
Pilot
passage obstructed
Infiltrations of air
Deformation
of float
Needle vaive
worn
or scratched
Needle valve insufficiently sealed
Fuel level
set
wrongly
Pifot
jet
set
wrongly
Starter
jet
obstructed
Malfunctioning
of
the
starter piston
Switches and conductors
Starter
POOR
ENGINE
COMPRESSION
—
Cylinder and
cylinder
head
•
Air
filter
element obstructed
Fuel
pump
defective
• Suction hose
obstructed
Piston
and
piston rings
Crankcase and
valves* crankshaft
TRBL
SHTG
m
PROBABLE CAUSES
• Electrodes gap
not correct
•
Electrodes
worn
• Feed
cable interrupted
•
Wrong
thermal grading
of spar1<
plug
•
Defective spark plug cap
•
Primary
or
secondary winding interrupted
• High
voltage cable defective
•
Defective
coil
•
Defective
unit
• Defective pick-up
coil
•
Woodruff tongue broken
Main
switch defective
Engine stop
emergency
switch defective
Harness with cable interrupted
Neutral switch defective
Starter switch defective
Side stand switch defective
Clutch switch defective
•
Starter defective
•
Defective
starter
relay
•
1
and/or 2 diodes interrupted
• Starter clutch defective
PROBABLE CAUSES
• Spark plug tightened
insufficiently
•
Cylinder
head
or cylinder insufficiently
tightened
•
Cylinder head gasket broken
•
Cylinder gasket broken
•
Cylinder worn,
damaged
or
seized
•
Piston rings
wrongly
assembled
• Piston
rings
worn, yielded or broken
•
Piston
rings
stuck together
• Piston seized or
damaged
Poor crankcase
sealing
Borders
of drive shaft
oil
seal
damaged
Poor
vaive sealing
Valves
and
housing with
insufficient
contact
Valves
out of
phase
Valve
spring
broken
Crankshaft seized
Camshaft
seized
•
9-1
9-2