Suzuki DF250S, Owner'S Manual, Page: 35 / 53

33
SPARK PLUG
Remove the spark plugs as follows:
1. Remove the bolt securing the ignition coil.
2. Pull out the ignition coil.
3. Loosen and remove the spark plug using the
box wrench in the tool bag.
Your outboard motor comes equipped with the
following “standard” spark plug for normal
usage.
Your authorized Suzuki Marine Dealer can
determine if the standard spark plug is suitable
for your type of motor usage by inspecting the
color of the plug’s porcelain center electrode
insulator after operation.
If the plug tends to run hot (usually evidenced
by whitening of the insulator or a burnt elec-
trode), stop using your motor immediately as
severe engine damage may result. If the plug
tends to run cold (usually evidenced by black-
ening of the insulator or a wet electrode), per-
formance may suffer. Ask your authorized
Suzuki Marine dealer to evaluate either of these
problems to determine the cause.
Standard spark plug NGK BKR6E
CAUTION
It is important that you use ONLY resis-
tor-type spark plugs. Non-resistor types
will interfere with the function of the elec-
tronic ignition, causing misfiring, or
cause problems with other electronic
boat equipment and accessories.
CAUTION
Use of improper spark plug can cause
severe engine damage.
• Do not experiment with other spark
plug brands unless you can determine
that they are directly equivalent to the
specified brand, or you may experience
engine damage which will not be cov-
ered under warranty. Note that after-
market cross-reference charts may not
be accurate.
• To install spark plug; seat it as far as
possible by hand, then use wrench to
secure to either recommended torque
setting or rotation angle.
Tightening torque
2.5 – 2.8 kg-m (18.1 – 20.0 lb-ft)
Rotation angle
New plug 1/2 – 3/4 of a turn
Re-use plug 1/12 – 1/8 of a turn
Do not overtighten or cross thread the
spark plug, as this will damage the alu-
minum threads of the cylinder head.
• Spark plugs must be seated properly
and securely tightened. Loosely
installed spark plugs may get abnor-
mally hot and engine damage could
result.
Center
electrode
Ground electrode
Insulator
Gap