1975 evinrude 9.9 ignition problem

[scanman]

Can anyone tell from these pics where a short might be? After a complete powerhead overhaul, carb, fuel pump, almost everything, it is shorting to ground intermittently. I'm sure it's somewhere under the flywheel 'cause I ran it last night & couldn't see the spark jumping anywhere, yet I can hear the telltale "tick, tick, tick" of the spark clearing a gap somewhere. The points are good & set correctly. The condensers are new. Timing checks out with an inductive light. Good bright blue spark jumps a 3/8" gap on both cylinders when it's present. It's intermittent on #2 cyl. Maybe there's a tecnique that I'm not aware of to isolate the problem. Thanks in advance guys!

 

[Vic.S]

Re: 1975 evinrude 9.9 ignition problem

I think if you can here a spark jumping to ground it'll be on the HT side of things rather than under the flywheel.
Perhaps try swapping the ignition coils over to see if the fault moves with the coil to No 1 cylinder.

Also, but separately, swap the plugs over.

That's the way to find faults, swap parts over from one cylinder to the other. When the fault moves with the part, bingo!

 

[oldcatamount]

Re: 1975 evinrude 9.9 ignition problem

You may need to take the ignition plate off to expose the rest of those two blue wires. I'm thinking your problem is with the solid blue wire (the blue wire with the white stripe is number 1 cylinder). Hopefully, someone else will help out here because I'm not really sure (but that's where I would look).

 

[beverly]

Re: 1975 evinrude 9.9 ignition problem

Thanks for uploading the pictures. I was wondering what it looked like inside the flywheel. I thought there was a spring or two keeping it stable when it bounced around.

 

[Daviet]

Re: 1975 evinrude 9.9 ignition problem

I agree with Vic.S, if you can HEAR the spark jumping it would have to be on the high HE side of the system. It would not be under the flywheel, but the coils are leaking to ground somewhere.

 

[scanman]

Re: 1975 evinrude 9.9 ignition problem

Ok, I'll swap the coils & try it again. Just thought I should've been able to see the spark jumping last night. BTW #1 coil is new & #2 is one of the old ones. I'll let yall know what happens.

 

[bktheking]

Re: 1975 evinrude 9.9 ignition problem

Run it in the dark.

 

[scanman]

Re: 1975 evinrude 9.9 ignition problem

Ok, swapped coils. Checked spark. Same problem, same cylinder. Runs on one cylinder for 30 seconds or so, & I can still hear it "ticking".
Beverly, Your very welcome. If you need other pics just send me a Private Message & I'll upload them for you. I have many more 'cause I just rebuilt the powerhead & almost everything else.
bktheking, I ran it last night. Didn't see anything jumping.

 

[Daviet]

Re: 1975 evinrude 9.9 ignition problem

Lets rethink this.
You have one charge coil to fire two ign coils, so you can't have 1/2 bad charge coil.
You have two ign coils that you have swapped and the miss stays on the same cylinder, that would leed me to beleave to think that boths coils are ok.
The only thing left in the ign system is the points and condenser for the seperate cylinders. I have never heard of a set of points causing a ticking sound, it stranger things have happened. Recheck your points, gap and condition. Are the points new? I fought a new set of points not working properly one time and it turned out to be a ground problem. I removed the points and scuffed up the point base and the contact area of the mag plate with sand paper and it cured my problem.
Did you swap the plugs also?

 

[scanman]

Re: 1975 evinrude 9.9 ignition problem

Daviet, I didn't swap the plugs, but I have tried three different brand new sets. I replaced the condensers after the rebuild, but just lightly sanded the points, cleaned 'em with contact cleaner, re-installed & re-gapped 'em. I think I'll go out now & pull the points and do the sanding you recommended.
I'll post results in about 1hr as all the tools are still out. Thanks

 

[scanman]

Re: 1975 evinrude 9.9 ignition problem

Daviet, sorry for the delay. Neighbors dog got run over & they weren't home so we took it to the vet! Prognosis fair, no broken bones, just watchin her real close right now! Poor li'l teacup Chihuahua! Anyway, did the recommended sandin under the points base & mag & the tickin stopped! MANY THANKS! Still runnin rough, but it's still on the break-in oil & keeps foulin plugs. Think it's ok to thin the oil out some? It's got 5.1 hrs so far W/ new crank, pistons, seals etc... Thanks again man! that was a big help!

 

[Daviet]

Re: 1975 evinrude 9.9 ignition problem

You're welcome, glad you got the problem fixed. I still don't under stand the ticking sound, but it's fixed and that's the important part. Happy boating.

 

[bktheking]

Re: 1975 evinrude 9.9 ignition problem

Spark snap perhaps?

 

[scanman]

Re: 1975 evinrude 9.9 ignition problem

Yes, bk, the tick was a spark snap. Like Daviet, I'm suprised I could hear it from under the flywheel, but after the powerhead rebuild, it's a LOT quieter! Maybe the new exhaust gaskets!?! LOL!
Thanks Ya'll!
This should be in the top secret file!