Normal.
Oxide
Fouling.
Wet,
Fouling.
Over
Heated.
1
Worn Out.
Conditions
I
I
5-4
Light brown
or
tan
few deposits
no burning.
Ash like deposits,
no wear.
Black, oily film and
carbon layer, not
worn.
Light grey or white,
burned.
Color
OK,
worn
electrodes.
Particles ‘fused
between ‘electrodes
Analysis
Plug is
O.K.
Deposits in combustion
chamber, clogged
exhaust ports or muffler,
wrong
oil
in fuel.
Replace.
Carburetor set too rich
weak ignition, air filter
clogged, too much oil in
Fuel, wrong plug (too
cold). Replace.
Carbon in exhaust ports
and/or muffler, dirty
cylinder fins, carburetor
set too lean, blade dull,
engine overload from
heavy cutting, wrong
plug (too hot). Replace.
Plug old, replace.
Excess carbon
in
cylinder from wrong oil
or fuel, wrong oil/fuel
mixture, clogged
exhaust
ports.
Replace.
To Next Page
Loading...
Need help?
General
