Service Manual

8-2 TROUBLESHOOTING
Engine Troubleshooting Guide
If the engine malfunctions, check if the way the
engine is used is correct. If engine malfunctions
even if engine is used correctly, systematically carry
out troubleshooting starting with simple points.
This chart describes typical troubleshooting
procedures.
Do not unnecessary disassemble carburetor,
magneto or engine unless it has been found to be the
cause of malfunctioning.
[Engine hard to start]
Remove spark plug and
check spark by cranking
engine while having the
plug touched against
engine block.
A
! WARNING:
Keep the plug es far away
ee possible from the plug
hole.
To avoid en electric
chock. do not hold the
plug itrelf.
Make sure to hold the
plug cep.
T
YES- @Faulty spark plug Replace
spark plug is replaced?
LYES.
L. --
’ LNO-j
I
I
l Faulty contact of plug - Correct
Are sparks
produced
between high tension
lead and engine block
when igniter is replaced7
Is compression sufficient7 h-YES-1 Make starting attempts a 1
,
'L
NO,
1 Check carb.
.
number of times and then
remove spark plug and
observe electrodes.
Are they wet7
.NOw
0 Plugged air hole in tank
l Check for plugged fuel
line.
l Check for plugged air
passage.
l Check float level.
l Check carb. setting.
L
l Wom piston/piston
- Replace
rings
l Stuck piston rings
- Clean or replace
l Worn cyl. bore - Bore or replace
l insufficient cyl. head - Retighten
tightening
l Faulty contact of valve - Lap
seat
@Plunge-up by valve
- Adjust valve clearance
0 Warped cyl. head
0 Broken valve spring - Replace
l Stuck valve
- Clean or grind
0 Burned head gasket - Replace