6-3
1
2
3
4
5
6
7
8
9
10
TROUBLESHOOTING
ENGINE SPEED DOES NOT INCREASE
ENGINE SPEED DOES NOT INCREASE
No. Checking steps Possible remedy
1 Check the spark plug for dirt and check the spark plug gap. Clean, adjust, or replace the spark plug.
2 Check the air filter element for dirt. Clean.
3
Check the compression pressure.
(Refer to “MEASURING THE COMPRESSION PRES-
SURE” on page 3-1)
Too high:
Decarbonize the combustion chamber if
there is carbon deposits.
Too low:
Next checking steps.
4
Check the valve clearance.
(Refer to “ADJUSTING THE VALVE CLEARANCE” on
page 2-11)
Adjust the valve clearance.
5
Check the valve face and valve seat for wear.
(Refer to “VALVE” on page 3-26)
Resurface or replace the valve face and
valve seat.
6
Check if the marks on the crankshaft and camshaft are
aligned.
(Refer to “INSTALLING THE VALVE LIFTER AND CAM-
SHAFT” on page 3-36)
Correct.
7
Check if there is seizure, wear, or damage on the piston,
piston ring, or cylinder.
(Refer to “PISTON, CAMSHAFT, CRANKCASE, AND
CRANKSHAFT” on page 3-32)
Rebore or replace.
8
Check if the main passages, such as the main jet in the car-
buretor, are clogged.
Clean the parts.
9
Check if there is air suction from the carburetor joint, gas-
ket, or throttle shaft.
• Tighten the carburetor nuts securely.
• Replace the carburetor joint or gasket
with a new one.
To Next Page
Loading...
