Logo

No spark

ThisIsNotaStep

New member
I have a 1977 Evinrude 9.9 model 10724A stalled out coasting into the dock and would not restart. It has no spark on either cylinder. Cleaned the plugs as they were badly carbonized. Checked continuity on shut off button, it's ok. Swapped in another power pack still no spark(same part number).
My father's son abused the heck out of it for 40 years and never had any problems. This is at a remote location that I go to on weekend’s only. Where do I go from here?
 
Last edited:
I assume you're saying that, pertaining to the "stop" button, it has continuity ONLY when it is pushed in?

Regardless, remove the spark plugs when checking for spark which should jump a 7/16" air gap with a strong blue lightning like flame... a real SNAP! Note that check spark with the spark plugs is a waste of time.

Spark testers can be bought at any auto parts store... ORE if you have the time, build the following.

(Spark Tester - Home Made)
(J. Reeves)

Most auto part stores have "air gap" spark testers... OR..........

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
***************

The wire that leads from the power-pack to that stop button... disconnect it temporarily. If still no spark, are you absolutely sure that the replaced power-pack is okay? Yes, even new ones have been know to fail sitting on the shelf!

Check the readings of the stator as per your service manual.
 
Sorry, and correct, the button only has continuity when pushed, it is operating correctly.
Not using a spark tester .. there is no spark in either cylinder.
I will try another power pack that I know is good.
The operators manual says nothing about the stator, how do I test it?
 
Stator test.... Sorry, I don't have the 1977 service manual so I don't know the exact readings. However......... pulling from memory and checking my 1979 manual, the ohm reading is 575 ohms +/- 75 ohms.

There are usually two wires leading from the stator to the powerpack, normally a Brown one and a Brown/Yellow one. Those two are the ones that energize the pack/s capacitor. You should get a ohm reading (unknown) between those two.... and NO reading between either of them and ground.

Also... visualize the stator closely if the new good known powerpack doesn't cure the problem. If a sticky looking substance should be dripping from it down on the powerhead area, replace it regardless of whatever reading you might obtain as that leakage would result in a AC voltage drop to the pack's capacitor.
 
Last edited:
Okay, thanks, ..

1) I will try a known working power pack,
2) then check the stator wires at the power pack,
3) then pull the flywheel and verify the stators condition.

I'll let you know Tuesday after our Cdn thanksgiving long weekend what happened ..
 
Well I checked the stator wires and there was no continuity :( ..
Thanks for the help, in future, where is a good place to find shop manuals for older evinrudes?
 
Wait a minute, my motor, model 10724A, does not have a stator, no electric start/alternator so it is a charge coil that is bad, I checked the brown and brown with yellow stripe wires....
 
Wait a minute, my motor, model 10724A, does not have a stator, no electric start/alternator so it is a charge coil that is bad, I checked the brown and brown with yellow stripe wires....

Yes... Charge Coil..... Same color wires which should emit a reading if good. Same unit function, smaller, different name. My apologies for not catching that.
 
kimcrwbr1 .. You jinxed me!
The standard lift the motor by the flywheel and tap on the top of the crank ain't budging it. Other than a flywheel puller, anyother methods, heat? If not I'm off to princess auto to get a puller.
 
Back
Top