4-2
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TROUBLESHOOTING
TROUBLESHOOTING
BEFORE TROUBLESHOOTING
• Check that the electrical connectors are connected securely.
• Check for sufficient fresh fuel in the fuel tank.
• Read the circuit tester's operation instructions carefully, and observe the instructions during inspection.
TROUBLESHOOTING
ENGINE DOES NOT CRANK
ENGINE CRANKS BUT WON’T START
• Check the oil level before troubleshooting (page 3-3).
Cannot be cranked
Abnormal
Cranks
Inspect the recoil starter (page 10-6).
Disassemble the engine and replace the faulty
part(s) (page 14-4).
Replace the faulty part(s).
Remove the recoil starter (page 10-2) and check
whether the engine cranks (turns over).
Perform the spark test (page 9-4).
Check for clogged fuel filter, fuel tank joint, and fuel
tube.
Perform the IGNITION SYSTEM
TROUBLESHOOTING (page 9-2).
Turn the fuel valve lever to the ON position.
Loosen the carburetor drain screw and check the
fuel flow from the fuel tank (Applicable types).
No spark
Does not flow
Check the cylinder compression (page 13-9).
Check the valve clearance (page 3-8), and then
perform the cylinder compression test. If the
cylinder compression is too high, remove carbon
deposits in the combustion chamber (page 3-8).
Check the decompressor operation of the
camshaft (page 13-6).
Check the valve clearance (page 3-8), and then
perform the cylinder compression test.
If the cylinder compression is too low, perform a
leak down test.
If there is no air leakage in the engine, check the
following.
- Valve spring free length (page 13-11)
- Valve seat width (page 13-9)
- Decompressor operation (page 13-6)
- Piston ring side clearance (page 14-10)
- Piston ring width (page 14-11)
- Piston ring end gap (page 14-11)
- Piston skirt O.D. (page 14-9)
- Cylinder sleeve I.D. (page 14-9)
If spark plug is correct, clean and dry the
electrodes and then restart the engine, taking care
that the choke valve is not closed too much.
If the engine does not start and the electrodes are
wet again, check the carburetor float valve (page
6-7).
Check the spark plug (page 3-6).
Disassemble the carburetor to clean the carburetor
ports, jets, and nozzles (page 6-6).
Spark
Flows
Compression
is too high
Compression
is too low
Wet
Dry
Normal
