| Malfunction | Possible Cause | Remedy |
|---|
|
1. Engine does not start despite properly functioning ignition and
adequate fuel in tank.
|
a) No fuel in fuel system.
|
a) Clean main jets. Check fuel supply lines. Detach fuel line
connecting pump with carburetor, actuate starter (ignition off). If
fuel flows from pump, float needle valve is plugged; if no fuel flows
from pump, possibly pump check valves are stuck or pump mechanism
defective.
|
| |
b) Carburetor floods. |
b) Check and clean float needle valve, check gasket at float needle
valve assembly. Check float, replace if defective.
|
| 2. Uneven idling. |
a) Improperly adjusted idling. |
a) Readjust idling. |
| |
b) Idle jets or idle air bleed plugged. |
b) Clean idle jets or idle air bleed, as required. |
| |
c) Leak in the intake ducts. |
c) Check intake ducts, flange connections, and gaskets. |
| |
d) Defective idle mixture screws. |
d) Install new idle mixture adjusting screws. |
| 3. Poor power transition (flat spot). |
a) Idle adjustment too lean. |
a) Readjust idling (check jets). |
| |
b) Improperly set float level. |
b) Readjust float level. |
| |
c) Improper injection quantity. |
c) Readjust injection quantity. |
| |
d) Intake ducts leaking. |
d) Check intake ducts, flange connections, and gaskets. |
| 4. Engine stalls when throttle is quickly closed. |
Improper idle adjustment. |
Readjust idling. |
| 5. Engine runs unevenly, misses, backfires. |
a) Mixture too rich. |
a) Check fuel pump pressure. Check float level. Check float needle valve. |
| |
b) Mixture too lean. |
b) Clean main jets. Check fuel lines. Check float level. |
| |
c) Intake duct leaking. |
c) Check intake ducts, flange connections, and gaskets. |
| 6. High fuel consumption. |
a) High fuel pump pressure overriding float needle valve. |
a) Check fuel pressure. |
| |
b) Defective float (leaking). |
b) install new float. |
| |
c) Float needle valve not closing.
| c) Check float needle valve. |
