Boating and Sailing.pdf - Moja ladja

Sparking Your Relationship
Chapter 22: Keeping Your Engine Happy
299
Without lots of fire, marine engines don’t run well. On outboards, the spark plugs and the
wires that lead to them stick out where they can be bumped or loosened by contact with
the cowl or by careless work on some other part of the engine.
Check the plug wires and connections regularly. Particularly on older motors, the connector
insulation sometimes goes soft and sticky, as a result of long exposure to gas fumes,
and loses its insulating capability. Replace any plug wires that are not firm and dry, and
make sure the connectors snap securely on the spark plug contacts.
With diesels like this
Yanmar, you can be sure that
the spark plugs are not the
problem. Diesels function
without them.
(Photo credit: Yanmar Diesels)
It’s not a bad idea to pull the spark plugs before the start of the boating season. Clean
them with a wire brush, check the gaps and adjust according to the manual, and then
reinstall.
Use a torque wrench to tighten the plugs. It’s
very easy to strip the threads in the aluminum
heads by overtightening spark plugs—don’t try
to do this by “feel” unless you’ve been a mechanic
for 20 years.
When you fit the cowl back in place on an outboard,
make sure that it doesn’t hit any of the
plugs or wires and cause problems.
The powerhead of an outboard runs in a mist of
wet air, with lots of salt along the coast. This soon
corrodes or causes electrolysis if the metals are
not protected. Spray down your powerhead
Look Out!
Any time you take the
cowl off an outboard, make
absolutely certain that the rubber
seal at the bottom fits back into
the casement around the powerhead.
Any misfit here or any failure
to properly clamp the cowl
back into place will let water into
areas where it shouldn’t be, particularly
if you use the boat in
big, following seas.