Trouble Shooting - International Harvester Company CUB Operator's Manual

TROUBLE SHOOTING
Mechanical Problems and their Probable Cause
If any trouble is experienced, xnake sure of the cause before attexnpt-
ing to xnake any adjustxnents. When xnaking an adjustment, keep in xnind
the previous setting in case the adjustxnent doesn't solve the problexn.
Possible Cause
Possible Remedy
HARD TO START
No gasoline in starting tank or carburetor • '. Fill the tank with gasoline; open the fuel shut-off
valve. Check the fuel lines, fuel strainer and
carburetor.
Fuel strainer orfuellines clogged . . • • . • Clean the fuel strainer, check the fuel lines and
Impulse coupling inoperative (tractors
with xnagneto) .•••
Water in gasoline.
Water in cylinders.
Choked ixnproperly. Flooded engine . .
Defective ignition or loose wiring ..
Defective battery or cranking xnotor
Spark plugs dirty or ixnproper gap.
Magneto grounded (tractors with
carburetor.
· Flush with kerosene;
see page
28.
• Drain the fuel tank and carburetor. Use new
fuel and dry the spark plugs.
*
Check the cylinder head gasket or look for a
clogged drain hole in the exhaust xnanifold or
xnuffler.
· Follow the st'arting instructions.
See pages
9
and
10.
Check the wiring, plugs, distributor and coil
unit, or xnagneto, etc,
See pages
25
to
40.
Check and service;
see pages
33
and
34 or replace.
Clean, adjust the gaps to .023 inch, or replace
the plugs.
xnagneto) . • . • • • • • • • . • • • . • . . • . • • • • . • Pull out on the ignition switch. Check for other
possible grounds; also see "Magneto"
on pages
27
Engine speed control not advanced.
Lack of coxnpression • . • . . • • • • •
Flywheel ring gear teeth broken •.
Lubricating oil of too high viscosity .•
Gears engaged •.•
Internal seizure ••.
to 30 •
• • • Advance the lever one-third for starting.
· *
· *
• Drain and refill with proper lubricant. See the
"Lubrication Table"
on page
64 •
• • • Put the gearshift in the neutral position.
· *
ENGINE OPERATES IRREGULARLY OR KNOCKS
Engine incorrectly tixned • • . • • • • • • . • • •
Spark plugs dirty; wrong gap or wrong type.
Poor or weak spark • . • • • • • . • • • • • . . •
Carburetor setting incorrect •.•
Poor grade fuel or water in fuel.
Engine overheating • . • • • . • • • •
Engine valves at fault • . • • • . • • •
Air leaks around intake xnanifold. •.
Engine sxnokes . • • • • • • • • • • • •
Retixne.
• Clean, reset the gaps to .023 inch, or replace.
Check the distributor and coil unit or xnagneto
to see if the spark is good froxn the coil. Check
the breaker points and breaker point opening,
spark plugs, and wiring;
seepages
25
to
40.
• • Adjust; see "Carburetor"
on page
11.
• • Drain and use a good grade of clean fuel.
Check the cooling systexn and fan belt; adjust the
radiator shutter if used; see "Engine Overheats"
on page 56.
• Check the valve clearance.
*
• Check the gasket and tighten the nuts.
• • Check the air cleaner oil level. Check the fuel
delivery at the carburetor. Check for worn
piston and rings.
*
Excessive carbon in engine . .
*
Loose piston pin or bearings . •
*
Broken rings or loose pistons. •
*
Worn connecting rod and xnain bearings
*
Governor sticking or needs adjustxnent.
*
*
See your International Harvester dealer.
55