No spark on a merc 140 horse...

Joined
Mar 25, 2009
Messages
20
Hey everyone. I've got a problem that I can't seem to nail down myself. Had an issue with my "new" boat the other day, wasn't getting fuel. So I replaced my fuel pump, now I'm getting plenty of fuel. Still won't start. Replaced the coil, still won't start, replaced the spark plugs, still won't start. I don't know what else I can replace. It seems to be electrical in nature, I checked the plugs and I didn't get spark on any of them, even though they are brand new (aka last weekend). My only other thoughts are the voltage regulator or the starter solenoid. I'm more of a mechanical guy, not an electrician. Please someone help!
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,345
Re: No spark on a merc 140 horse...

And would this be points or electronic ign.?
do you have 12V at the + side of the coil with the key in the "RUN" position?
is the safety lanyard operational?
 
Joined
Mar 25, 2009
Messages
20
Re: No spark on a merc 140 horse...

And would this be points or electronic ign.?
do you have 12V at the + side of the coil with the key in the "RUN" position?
is the safety lanyard operational?

It's a point ignition, the wiring hasn't been touched since it was last run. It's just been sitting for about 6 months before I bought it. There is no kill switch installed (next on my list of things to do after I get it running). It's a 1984 model if that helps, the rotor and cap are in almost perfect shape, the wires look brand new and have no corrosion on them, plugs are brand new and so is the coil. Would the voltage regulator or the ignition solenoid be more to blame?
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: No spark on a merc 140 horse...

99% of the time on marine engines with a points ignition, after setting for a while the points glaze over and will not make contact. That is why a tuneup, (points, condenser, spark plugs, dwell set, timing set, advance timing check, carb mixture and idle speed) are recommended yearly.

File the points with a points file just to see if that is the problem, then replace them no matter what else happens.
 

PowerAddict

Chief Petty Officer
Joined
Aug 8, 2007
Messages
418
Re: No spark on a merc 140 horse...

99% of the time on marine engines with a points ignition, after setting for a while the points glaze over and will not make contact. That is why a tuneup, (points, condenser, spark plugs, dwell set, timing set, advance timing check, carb mixture and idle speed) are recommended yearly.

File the points with a points file just to see if that is the problem, then replace them no matter what else happens.


Not that I'm a boat expert, but its happened to me after sitting all winter last two years. File or sand the points and I bet it'll start right up.
 
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