Re: Evinrude Lightwin problems

[johnyrude200]

quote BillW:

However, it can also mean a fouled plug. I would throw in another set and retry. A cheap and easy experiment. I have been fooled by a sub-par plug, that I thought was okay, before. You might also try backing each plug boot off the plug, while the engine is running, using insulated pliers. (Purpose-built, plastic pliers are best.) Sometimes, a fouled plug will pick up and start firing, if the ignition is made to produce its full voltage potential this way.

If you haven’t checked the strength of your spark, this could mean you have low voltage coming from that lead. Before swapping plugs, swap plugs on the cylinders. If the same cylinder is presenting the same issue, then you ruled out plugs and saved yourself a few bucks. If the problem migrates with the plug swap, then you confirmed it is the plug. Go get an air gap spark tester from your local automotive store, in fact, buy two. 1 for each lead. They cost about $8 each and are a must-have for problem diagnosis with ignition systems. Without the proper testing equipment (I.E. merctronic), it’s going to be a trial-and-error approach evaluating your coils, condensors, and points.

Old plug wires can cause a huge amount of problems too. If your wires are dry, taking permanent form, then get new ones. Although you may not SEE any holes, chances are there is a ton of electricity leaking out of those wires if they are originals or just old/dried out. Pull your plug boots off and see if the end of the leads are corroded, this is common. If so, snip off an inch, and if salvageable, re-install the boot and terminal. Check your coil to wire connections too.

Remember plug wires are like water pipes. They leak electricity just like a leaky water pipe. Problem is you almost never see the electricity leaking out. If you have weak spark, you have to go backward through the system step by step to race the root of the problem.

If you have low spark on that cylinder, it’ll run right at the low end but then miss at higher RPM due to higher compression in the cylinder. That means you have something wrong with that half of your magneto system. It’s possible you have a timing issue too, but that’s a long shot.