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JSE
 
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Default How To Diagnose an OB Problem (was about plug wires on Evinrude outboard)

sound advice. go for it. the spark tester looks like a board with adjustable
contacts on it. Just in case you didn't catch the
warning.........ground the spark tester


"Brian Whatcott" wrote in message
...
On Sun, 23 May 2004 18:26:14 GMT, wrote:

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


Do this:
Buy a chamois leather and a funnel: buy a plug hole compression
tester.: buy a spark gap tester. This should total less than $30.

While running, does the motor pick up if you pump the bulb?
(Float needle valve, dirty idle jet, idle adjustment)

Shake the gas tank up, then pour some gas through a chamois leather.
Are there any visible specks at all?

Unscrew all plugs, GROUND the ignition leads (I AM SERIOUS)
Test the compression of each cylinder in turn, running the starter for
2 or 3 revs each time.
All values should be over 105 psi and all should be within 10%

Look at the spark plug electrodes - are they grey, black or shiny
clean?
Grey OK, black = rich, shiny clean = water leak in the head gasket
(easily fixed)

Hook up the ignition tester with a gap set to about 35 thou.
Is there a good blue flash as you turn the starter over?
Each plug? (Don't leave loose ignition wires ungrounded - I warned
you)

When you have these five results in hand, there are people who will
tell you how to fix it up......

Brian Whatcott Altus OK