evinrude no spark 9.9 (1976)

[Bubbles Up]

Hi folks,

I just towed my buddy in from the lake, he said his motor was running like a champ, then he said it dropped the top cylinder so he would swap the two leads around. He was half way back. Total dead, no spark on either. At the boat launch we pulled the flywheel there was quite a bit of rust on the magnets in the flywheel, I gave it a scuff with a white Scotch-brite pad they looked a HECK of a lot cleaner. We put the motor in gear and spun the prop by hand could see both sets of points opening. Replaced the flywheel and torqued the nut. Disconnected the kill switch leads from the coils gave a few pulls, no spark on the tester.
Any ideas?

 

[racerone]

Re: evinrude no spark 9.9 (1976)

Are you sure that disconnecting the kill switch wires is the correct way to test on this particular motor ?-----A bit of rust on the magnets has no effect on the magnetic fields.---------Test the driver coil and make sure that both sets of points are abosuletly clean.

 

[Bubbles Up]

Re: evinrude no spark 9.9 (1976)

Racerone. ~ Thanks for the quick reply!

We just disconnected the kill switch by unplugging them. We did run a piece of 220 sandpaper, folded in half and drawn thru a few times each set of points. We have since took both coils off and tried them on my motor they test perfect as they fire my motor.

 

[racerone]

Re: evinrude no spark 9.9 (1976)

Points must be absolutely clean in order to work on this system.-----Working on a 74 model and will let you know whether kill circuit is normally open or closed.

 

[bwkre]

Re: evinrude no spark 9.9 (1976)

A 76 9.9 has three coils, One coil for each plug, located on the side of the block near the head. The third coil is located under the flywheel, it is the driver coil. The driver coil with the condensers and points produce a voltage to operate the plug coils. If you have electric start then there will also be alternator coils under the flywheel. If both cylinders have no spark the look for the problem in what is common to both. The driver coil or deadman switch. If you lost spark in the top cylinder first then it could be that coil which may have damaged the driver coil through prolonged use. Attached is a diagram from the 76 service manual model 10624, 25

 

[OptsyEagle]

Re: evinrude no spark 9.9 (1976)

I suppose I have more questions then answers. When you said no spark on the tester, is that an inline tester connected to the spark plug or an external spark gap tester. The reason I ask is that these motor are prone to spark plug fouling and I wonder if you have isolated that culprit from your testing. Have you tried new spark plugs and preferably NGK B7HS plugs?

I am also not sure what you mean when you say that he dropped the top cylinder and then he swapped the two leads around and then nothing from either cylinder. Did he just swap the spark plug boots to the alternate cylinders or did he do something else. Also, if he did swap spark plug boots, did he also swap the clips coming out from under the flywheel. If he didn't swap the clips as well, then that is your reason for NO cylinders firing. The spark will now be timed to fire at "bottom" dead center and no motor will run like that. Perhaps I am confused here.

Lastly, I would hook your kill switch back up since it sounds like this problem is something that is effecting the cylinders individually not something that serves them both at the same time. The kill switch kills them both and his problem you say started in the top cylinder. I am still not convinced that the bottom cylinder is not OK, since perhaps the timing was altered on it by switching the leads.

 

[Bubbles Up]

Re: evinrude no spark 9.9 (1976)

@ Bwkre - Thanks for the diagram. Will be looking int this thing further.

@OptsyEagle - We used an external spark tester, looks like a spark plug no threads and a gator clamp. We did change out the plugs, with my new spares (NGK B7HS). My buddy did a spark test on the water by removing the plug and grounding it out. just goin by what he said, figuring put the plug on the bottom and got spark. At the launch, we tried again with my tester, even had him grab each plug while I pulled the rope! Sure way to tell buddy does the "funky chicken" you have juice! LOL!!
His coils from the side of the block, were swapped to my motor and my motor fires up in the test garbage can.
The kill switch has been reconnected and things are put back into location for further trouble shooting. I'm sure with the good people on this forum this will be up and running soon.

Q. How do I test a driver coil?

 

[tanuki]

Re: evinrude no spark 9.9 (1976)

1974 Evinude 9.9 service manual states......"Driver Coil Test" (driver lead must be removed from points** Connect coil leads to an ohmmeter set to low ohms scale. Coil is good if resistance checks 1.45 (plus or minus .4 ohm).

 

[oldboat1]

Re: evinrude no spark 9.9 (1976)

maybe include just a simple minded continuity test of the plug wires -- test for continuity from the coil end of the wire (point of the tester through the wire insulation), to the plug end -- test up in the boot at the spring connector. The wire can be bad or (probably more likely) the connection for the plug may be corroded.

 

[Bubbles Up]

Re: evinrude no spark 9.9 (1976)

Update:

I pulled the driver coil off today and put the ohms tester leads to the wires from it , I 000 across the screen, the same as if I touched the 2 leads together. I guess the driver coil is pooched?

 

[bwkre]

Re: evinrude no spark 9.9 (1976)

Quoted from the 76 9.9 manual

" Driver coil test ( driver leads must be removed from points )
Connect coil leads to an ohm meter set to low ohms scale. Coil is good if resistance checks 1.45 + /- .4 ohms (rope start model) , or 2.70 +/- .7 ohms ( electric start model).
With driver coil leads still disconnected, connect ohmmeter (HI ohms scale ) between either driver coil lead and ground. Infinity reading indicates good driver coil. Any or zero reading indicates leads or driver coil is shorted to ground and should be replaced"

If you have the coil removed "ground" would be the metal laminations on the coil.
An analog ohm meter is best for the above tests but you can use a digital meter.
When use the hi ohms scale do not touch the meter probes with your fingers as it will affect your results.

I don't understand your reading of 1000 across the screen? What scale were you on to get that reading? Don't toss it yet. If your not on the right scale you wont get the correct reading

 

[Bubbles Up]

Re: evinrude no spark 9.9 (1976)

Bwkre,

I made sure that my ohms tester was on the 2000ohm scale(low as mine goes) . From the port lead(blue/white stripe) to the grounds screw the reading was 000. the starboard lead (blue) to ground screw was 002. Lead to lead was 000. They were disconnected from the points, and the probe went thru the rings making contact wit 2 places.

 

[bwkre]

Re: evinrude no spark 9.9 (1976)

If you get a reading of zero from a coil wire to ground, same reading as when you touch the tester probes together, then there must be a short from the coil lead to ground. The reading from coil wire to ground SHOULD be infinity, the same as if you held the meter probes in the air touching nothing. Anything less than open, or infinity, is a shorted coil. I would assume from what you are saying then , the coil is shorted or pooched as you put it.

Hope you get it sorted out.