Toro Greenmaster 1000 Service Manual page 82

NORMAL
Has gray or light tan deposits on the firing
tip.
LEAD FOULED
Has dark black, gray, tan, or yellow depos-
its. May have a fused glazed coating on the
insulator tip.
Caused by highly leaded gasoline.
Replace the plug.
GAP BRIDGED
Gap between electrodes is closed by de-
posit build up.
May be caused by carbon or oil fouling.
Replace spark plug.
Electrical System
OVER HEATING
Light gray or white insulator with small gray
brown or black spots. Electrodes have a
bluish burnt appearance.
May be caused by engine over heating,
loose spark plugs, wrong fuel type, too hot
a plug, low fuel pump pressure, or incorrect
ignition timing.
Replace spark plug.
CARBON FOULED
Black dry fluffy carbon deposits are found
on insulator tips, electrodes, and exposed
shell surfaces.
Weak ignition, too cold a plug, fuel mixture
too rich, defective fuel pump, excessive id-
ling, or improperly operating heat riser may
be the cause.
Replace spark plug.
OIL FOULED
Wet black deposits can be found on elec-
trodes, insulator, and in the bore.
Excessive oil entering the combustion
chamber through excessive clearances be-
tween valve guides and stems, worn or
loose bearings, or worn rings and pistons.
Replace spark plug.
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FUSED SPOT DEPOSIT
Has spotty or melted deposits resembling
blisters or bubbles.
Caused by sudden acceleration.
Replace spark plug.
WORN
Has a severely eroded or worn electrode.
Caused by normal wear.
Replace spark plug.
PRE–IGNITION
Electrodes are melted and the insulator
may be blistered. Metallic deposits on the
insulator indicate engine damage.
Engine over heating, burnt valves, too hot a
plug, incorrect ignition timing or advance, or
wrong type of fuel are causes.
Replace spark plug.
Greensmaster 1000/1600