TOHATSU BFT 250A Owner's Manual page 91

MAINTENANCE
Plug needing
New plug
replacement
7. Inspect the spark plugs.
(1) If the electrodes are heavily
corroded or carbon-soiled, clean
with a wire brush.
(2) Replace a spark plug if the
central electrode is worn.
The spark plug can wear out in
different ways.
If the sealing washer shows 
signs of wear, or if the 
insulators are cracked or
chipped, replace the spark plugs.
88
SIDE ELECTRODE
1.0 – 1.1 mm
(0.039 – 0.043 in)
8. Measure the plug gaps with a feeler
gauge. Correct the gap, if
necessary, by carefully bending the
side electrode.
The gap should be:
1.0 – 1.1 mm (0.039 – 0.043 in)
9. Thread the plugs in by hand to
prevent cross threading.
10. After the spark plugs are seated,
tighten with a spark plug wrench
to compress the washers.
If installing new spark plugs, tighten
1/2 turn after the spark plugs seat to
compress the washers.
WASHER
If reinstalling used spark plugs,
tighten 1/8 – 1/4 turn after the spark
plugs seat to compress the washers.
The spark plugs must be securely
INSULATOR
tightened. An improperly tightened
plug can become very hot and may
cause engine damage.
11. Install the ignition coil. Reinstall
the bolt.
12. Push the wire connector onto the
ignition coil. Make sure it locks in
place.
13. Repeat this procedure for the
other five spark plugs.
14. Reinstall the covers. When
reinstalling the covers, make sure
not to jam the wire harnesses in
between the covers and engine
case.