Coil test on Evinrude 115.

I need a little guidance on testing my coill my engine does not idle properly but if I can get it to idle and get it in gear it will run. I would like to test the coil can I have an analog meter set to zero. I removed it from the boat. I go from the lead from the power pack to ground and I'll get 250. I go from the league of the power pack to the spark plug lead and I get nothing. Spark plug to ground I get nothing.am I doing it right? What should I get in any combination of connecting a meter.

Thanks steve

What are the results of a compression test ?-----If spark jumps a gap of 3/8" or more the coil is good !-----Model # of your motor is ?

115693G.......not sure of compression. Or how to do it
I suspected the coil because I pull the wire while it is running....no real change....I want to do the obvious before I have to take it in. My first issue it would do nothing when I turn the key and I replace the solenoid and that fix that problem then I replace the spark plugs and it did crank better and want to stay running but it dies almost like it's not idle fast enough but I can hear it Miss

I would do a compression test before spending a penny on this motor.-------What happens when you install one of the other coils on that cylinder that " does not change " the way it runs ?

When I pull the wires on the other cylinders I notice a change but I just now bought a compression check gauge seems easy enough it will be here on Monday which works out because it's the weekend now and it's a busy sport weekend for me go Astros.

What PSI should I read on this engine?

Thanks for your help and advice. I will post again next week.

I read your original post several times before I understood what you are trying to tell us. My first thought is you have your multimeter set to the wrong range for what you are testing. But if that is not true, then the coil is no good.

Thank you....I will check for the setting... I also have my compression check tester now so I plan to do that tomorrow

115693G = 1976 115hp Evinrude

With all spark plugs removed, the engine must crank over at least 300 rpm in order for the ignition to be energized.

Using a spark tester whereas a 7/16" "Air Gap" can be set for the spark to jump, the spark should jump that gap with a strong blue lightning like flame... a real SNAP! Does it?

Single cylinder air gap testers are available at auto part stores. A multi cylinder tester can be built as follows:
********************
(Spark Tester - Home Made)
(J. Reeves)

You can use a medium size philips screwdriver (#2 I believe) inserted into the spark plug boot spring connector, then hold the screwdriver shank approximately 7/16" away from the block to check the spark or build the following:

A spark tester can be made with a piece of 1x4 or 1x6, drive a few finishing nails through it, then bend the pointed ends at a right angle. You can then adjust the gap by simply twisting the nail(s). Solder a spark plug wire to one which you can connect to the spark plug boots, and a ground wire of some kind to the other to connect to the powerhead somewhere. Use small alligator clips on the other end of the wires to connect to ground and to the spark plug connector that exists inside of the rubber plug boot.

Using the above, one could easily build a spark tester whereas they could connect 2, 4, 6, or 8 cylinders all at one time. The ground nail being straight up, the others being bent, aimed at the ground nail. A typical 4 cylinder tester follows:

..........X1..........X2

.................X..(grd)

..........X3..........X4

This can obviously be modified to a 6 or 8 cylinder setup tester.
********************
If encountering just one coil failure... one cylinder not firing and you suspect a bad coil...... Simply remove the timer base wire from the powerpack that is firing a good coil... and temporarily attach it to the non firing coil primary wire terminal of the powerpack, then crank the engine over with the tester attached to the spark plug wire. If that coil now fires, then obviously the coil is okay.

I still have the issue....I definitely had a bad coil . First I made sure all cylinders had compression. I would say they all had 125 to 130 psi...I then replaced the bad coil thinking first sure it would idle now. It did not! SO, I decided I better check all the coils . I disconnected them completely removing the ground from the motor and the hot lead to the power pack and they all tested good. Where do I check k next? Could it be the power pack itself ..I guess it could be carburator but my son said it ran good for him in may or June. Or linkage?

No answer on the spark jump here.------Powerpack is not big coins.------Sure try a new powerpack.

I'm I. Correct to assume that the power pack tells the coils to fire? To test the spark jump of the coil I use a screw driver put into spark plug boot of the coil I'm testing and hold it close to the block and turn the key? Is it ok to have the other three coils still connected to the plugs? Also should I disconnect kill switch so it doesn't try to start? Or does that not fire the coil.

Sseaback said:

I'm I. Correct to assume that the power pack tells the coils to fire? To test the spark jump of the coil I use a screw driver put into spark plug boot of the coil I'm testing and hold it close to the block and turn the key? Is it ok to have the other three coils still connected to the plugs? Also should I disconnect kill switch so it doesn't try to start? Or does that not fire the coil.

Click to expand...

No, a screwdriver held close to the block is not the right way to do this. Follow Joe's instructions exactly to perform spark tests which requires ALL spark plugs to be removed. Do not disconnect the kill switch because you won't get spark on any cylinder.

You need to use a correct adjustable air gap spark tester to do this properly: https://www.autozone.com/test-scan-...ls-adjustable-ignition-spark-tester/10257_0_0

Also, you might want to run the engine at night and look for places where the coils are arcing to the block. The outer shell of old coils can crack leading to it shorting out to the block. I'm not saying that is definitely your problem, but it's another thing to look at.

Poor idling can also be a case of imbalance between the carburetors. You need to make sure all throttle plates are full closed at idle and that they all open simultaneously and evenly. This is called sync and link. If one or more plates are open or closed more than others it will cause an imbalance of rich/lean mixtures that can cause improper idling.

You know I am leaning towards carburetor now because it starts right up and it only dies when I lower the warm up lever all the way. I saw on YouTube that the power pack can be tested by removing the lead from the coil and use a test light to touch contact on the power pack while turning the key. Does that sound right. I'm not sure how to do the linkage and said all that stuff on the carburetor so I may have to take it to somebody but of course I was trying to save the money. Rhanks for your help...
Also I think this is what Joe said.:
You can use a medium size philips screwdriver (#2 I believe) inserted into the spark plug boot spring connector, then hold the screwdriver shank approximately 7/16" away from the block to check the spark or build the following. 1st he said to buy a tester.