arc-over

[bfi]

Well folks 1976 70 hp stiiiiiiiiiill giving us fitts. This motor had a factory recall on the carbs that was never addressed. Now I'm wondering if it had a service buletin recall pertaining to the ignition system. It is driving me nuts . This motor had sat up for years and years --at least 12-15 that we know of I honestly feel it never ran worth a flip and has spent the bulk of it's time in the barn, parked out in the pasture, or in the mechanics shop. My friend inheritted it from his uncle and we've been having fun??? with it ever since. We have both been humbled by this beast to the level we could become monks or something. It has new coils, new plugs, new power-pack, carbs rebuilt, linked and synced, timing set, compressions has been tested and fine and have done every resistance type test we know of to do with ohm-meter but still need to do an output test from stator. The problem is it is arcing over at the plugs. Yes we tried the greese and even switched to ql plugs offed some improvement but still having issues. I forgot to mention we changed the rectifier as well. The coils we got were from evinrude dealer and were the old style just like what came off it. Who know and were probably new old stock from how long ago???. The spring clips on the end are ther push thru type. Just a barb pushed thru the wire type system. As experiment 742 we are going to solder those connections to see if offers any improvement. Any advice from those who have been thru this would be greatly appreciated.

Thanks in advance--John

 

[ezeke]

Re: arc-over

To start with, be sure that the plugs are Champion
QL77JC4, and set at .030.

The spark plug wires have to be solid core - auto wires will not work because the voltage is too high.

All grounds at the engine must be in great shape, so remove each component including the coils and clean to shiny metal.

 

[Silvertip]

Re: arc-over

Spark takes the path of least resistance. Get rid of the grease, get rid of the spark plug wires and boots, and get rid of the goofy spark plug clips on the end of the wires. Replace the wires and use NGK motorcycle spark plug connectors, and be sure they do NOT have internal resistors. As was mentioned, spark plug wires need to be wire core, not resistor wire. Your arcing problem will go away.

 

[jay_merrill]

Re: arc-over

The NGK wires sound fine but don't use NGK plugs. I don't really know why but these motors flat out don't like them. My OMC dealer mentioned this to me once and he was right - I tried a set on my 1972, 65hp and my motor ran terribly. As soon as I took them out and put Champions back in, all was well.

While you have replaced a lot of components, you are still dealing with an older motor. You may have some insulation on the wiring that has become brittle so that is an area that I would take a look at.

As for the stock OMC plug wires, spring coils and boots, I have a few thoughts. First, when you inserted the new wires into the new coils, did you twist them in the get a good seat? The wires will not fully seat if you don't do this. Also, did you use a little high temp silicon at the junction of the wires and coils, after fully inserting the wires? Finally, although this should not cause arcing that you can see, are the bared ends of the new wires touching the spring coils after the boots are put on the wire. Sometimes they don't when assembling this end of the wire as OMC shows you. What I do is to trim the insulation back a wee bit further, spread the spring coil with a small screwdriver and put the tip of the bared wire in between a couple of the coils before piercing the insulation with the "pointy end" of the sping coil. I think this assures me a better connection that stays in place, just in case I didn't get the barb portion of the coil exactly in the center when I push it into the wire, piercing the core of the wire.

 

[bfi]

Re: arc-over

Thanks for the replys folks! I actually have called a local cycle shop about wires boots etc etc etc this morn and as soon as I can will get by there. They offered a variety of options that sounded interesting and perhaps less cheesy. I really like the idea of spreading the coil and feeding the wire thru that's pretty clever. This is truly a super clean old motor and I feel like we are just 3 hairs away . We will check all grounds again. Also plan on replacing the battery cables as they are original insuation and looks marginal and a bit cracked in places

Thanks John

 

[bfi]

Re: arc-over

Thanks! I will press on with some this new info and ideas and let ya'll know how it all works out.

John

 

[samo_ott]

Re: arc-over

Anyone know if the '76 55hp had a recall on the carbs?