Engine Speed Is Uneven - Yamaha EF2200iS Service Manual

OTHER TROUBLES

ENGINE SPEED IS UNEVEN

1
No.
1 Check the fuel level.
2
2 Check if fuel has deteriorated.
3 Check the spark plug for dirt and check the spark plug gap. Clean, adjust, or replace the spark plug.
3
Check if there is air suction from the carburetor assembly
4
4
joint, gasket, or throttle shaft.
5
Check if the main passages, such as the carburetor assem-
5
bly, are clogged.
Measure the valve clearance.
6
6 (Refer to "ADJUSTING THE VALVE CLEARANCE" on
page 2-21)
7
Check the valve face and valve seat for wear.
7
(Refer to "VALVE" on page 3-21)
8
Check if there is seizure, wear, or damage on the piston,
piston ring, or cylinder.
8
(Refer to "PISTON, CONNECTING ROD, CRANKSHAFT
9
AND CRANKCASE" on page 3-33)
Check the throttle control motor.
10
9 (Refer to "CHECKING THE THROTTLE CONTROL
SYSTEM" on page 5-15)
Checking steps
6-6
Possible remedy
Add the fuel if it is insufficient.
Replace the fuel.
• Tighten the carburetor assembly nuts
securely.
• Replace the carburetor assembly joint
or gasket with a new one.
Clean the parts.
Adjust the valve clearance.
Resurface or replace the valve face and
valve seat.
Rebore or replace.
Replace the throttle control motor.