1975 Evinrude 115 Charge Coil / Stator testing

[leadpencil2]

Looking for someone to double check my readings before I spend the bucks to replace the charge coil.
While on the lake over the weekend, I was pulling the kids on the tube and the engine started to misfire and then quit. I did some testing last night and did not find any loose or bad grounds, determined it was not the kill terminal from the key switch nor the neutral start switch.
The sensor coil ohms reading was within spec (8.5 +/? 2.0 ohms) as well as ground check.
When testing the ohms reading for charge coil my readings are significantly higher than the 630 +/- 50 spec (1051 ohms). See photo 1

I also did a ground check on each of the charge coil terminals and both readings (1620 & 1844 ohms) are not within the specification outlined in my service manual (Any or zero reading indicated leads or charge coil is shorted to ground). See photo 2 & 3

Just wanted a 2[SUP]nd[/SUP] opinion on my findings, look like to me that I need a new charge coil.

 

[Joe Reeves]

With all s/plugs removed, did you do a spark test first to see if the spark would jump a 7/16" air gap with a strong blue lightning like flame... a real SNAP!? If not do so before you start throwing parts at that engine. (All s/plugs removed during that test)

If no spark exists, remove the black/yellow wire from either the powerpack..Re-try the spark test. If you have spark with that wire removed, either the ignition switch has an intermittent short or the black/yellow wire leading to it has a conductance short to ground... usually the switch, in which case, replace it.

The stator..... in viewing it closely, do you see any sticky looking substance dripping from it down on the powerhead area?

Has your tachometer been acting up lately.

 

[leadpencil2]

So after further inspection there is a lot of the sticky insulation that has melted and pooled on the powerhead. I use an inline spark tester light on all 4 plugs before doing anything (no spark) I also removed the black/yellow wire and confirmed the ignition switch is good (no spark). With all the insulation melted from the stator looks like I'm in the market for a new one. Any thoughts on a used stator vs new? The 300 - 400 price tag is really high.

 

[Faztbullet]

Needs a rectifier also....

 

[Joe Reeves]

So after further inspection there is a lot of the sticky insulation that has melted and pooled on the powerhead. I use an inline spark tester light on all 4 plugs before doing anything (no spark) I also removed the black/yellow wire and confirmed the ignition switch is good (no spark). With all the insulation melted from the stator looks like I'm in the market for a new one. Any thoughts on a used stator vs new? The 300 - 400 price tag is really high.

It's quite unusual for that type of V4 stator (low amp) to melt down. As Faztbullet indicates, the rectifier has probably been out of the circuit for some time which would restrict the stators output which in turn brought on the meltdown... so yeah, plan on getting one of those small 3 wire rectifiers also.

A used stator, with no cracks, and absolutely no indication of a meltdown would probably be okay... figure the price at about 75% off list.

 

[leadpencil2]

I pulled the old stator out tonight and made note of the part number 510839 which after some googling belongs on a 1973-1977 3 cylinder engine. Could this have contributed to the meltdown? I'm showing the correct part number is 581225. The rectifier is cheap enough so I'll order one of them as well. In looking at wiring on my engine I also have a voltage regulator in play (Part #511404) I don't see anything in my manual regarding the regulator, do I need to replace this as well?

 

[Joe Reeves]

I'm not versed on the regulator, whether it's good or bad or how to test it. However on a stator with low amps output, it's not needed... only the rectifier is needed. 581225 is the proper part number of the stator.

Note that the rectifier will not tolerate reverse polarity... even a touch of a fraction of a second will destroy it.