If it runs OK just off idle, then it's not as likely to be the ignition
system. Same goes for the compression system. What's left is the fuel
system. Noting that your carb(s) have 2 fuel circuits, one for running at
idle (tiny holes, "idle jets" in the side of the venturi) and one for
running off idle and faster (the main jet and up through the (typically)
straw/tube that extends into the venturi). At idle, there is not enough
airflow through the venturi to pull fuel through the main-jet fuel route and
that's why there has to be tiny 'leaker' holes or "idle jets" to provide
fuel flow at idle. At faster rpms, fuel comes in through both and whether
or not the idle jets are plugged or not doesn't make any difference. That's
why I said that if it runs OK just off idle, then it's probably not
ignition. Ignition systems fail more often so people always think of them
first, but idle/fuel related issues come next (or cooling/impeller/pump
problems). So go see if the motor smooths out as you pick the rpms off idle
and if so, have the carb cleaned and adjusted. You might have a particle of
something plugging your idle jets. If your carb has a float-bowl combo on
it (most do) it could also be flooding out from a sunken float ...what color
is the exhaust? Does it run rough and produce unburned fuel in the exhaust
for a minute and then tend to smooth out? Black or gray or white smoke is
excess fuel coming through incompletely burned while blue is oil coming
through.

Brian


--
http://www.advantagecomposites.com/tongass -- My 22' Tolman Skiff project
http://www.advantagecomposites.com/catalog -- Discounted System Three
Resins products


..
wrote in message
...
Hi,

I have a 1979 Evinrude 115 outboard. Recently it started
running very badly (often stalling out) at low rpms. So I
changed the plugs, and that didn't help at all. Someone
suggested I change the plug wires, but there turns out to
be more to it than that...each plug wire appears to be
permanently attached to what looks like a coil of some
kind. Two of them are joined together by 2 smaller wires
--one end of each is attached to a coil, and the other
end of both are attached to the same connecting plug.
There are four spark plugs, and two pairs of the coils.
Can anyone explain something about the setup, what
the parts I'm looking for are called, an economical place
to get them, etc?

Thank you for any help!
David