MASSEY FERGUSON MF 135 Operator's Manual page 68

4. Faulty coil. Remove high tension
wire from center of distributor and hold end
of wire about 1/4" from suitable ground.
With ignition switch ''on'', crank engine and
note if coil produces spark. It should pro-
duce a strong blue spark, not a weak yellow
one.
If no spark occurs, check all primary
wiring before condemning coil.
Engine Cranks but Will Not Start -
Carburetion Failure
1. Choke not pulled out when engine is
cold.
2. Throttle closed.
3. Fuel shut-off valve not open.
4. Fuel tank empty.
5. Clogged vent in fuel cap.
6. Clogged fuel filter or screens.
7. Restricted fuel line.
8. Restricted carburetor passages.
9. Water deposited in carburetor. In
cold temperatures, water freezing would
prevent gasoline flow.
10. Air cleaner inlet tube restricted.
11. Clogged air cleaner.
12. Throttle and/or governor linkage in-
operative or incorrectly a~justed.
13. Air leak in fuel line.
14. Cracked or broken intake manifold.
15. Valves sticking.
Engine Cranks Slowly
1 . Weak battery.
2. Crankcase oil too heavy for temper-
ature.
3. Defective starter or connections.
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Excessive Fuel Consumption
1. Fuel leak.
2. Fouled air cleaner.
3. Timing off.
4. Automatic spark advance not working
properly.
5. Distributor points need replacing.
6. Spark plugs need servicing or re-
placing.
7. Faulty wiring.
8. Improper valve timing.
9. Burned, worn or sticking valves.
10. Worn pistons, rings or sleeves.
11. Improper valve adjustment, worn or
bent push rods.
12. Engine overheating.
13. Clutch slipping.
14. Brakes dragging.
15. Excessive exhaust back pressure.
Excessive Oil Consumption
1. Oil leak.
2. Plugged breather pipe.
3. Worn valve guides.
4. Worn, broken or ill-fitted rings.
5. Worn, scored or out-of-round cyl-
inders or pistons.
6. Worn ring grooves .
7. Inverted rings.
8. Stuck piston rings.