1980 70hp Evinrude no2 cyl no spark

[FUL_005]

I have a problem that I cant solve, its a E70TLCSA so 1980 3cyl tilt & trim with intermittent no spark on number 2 cylinder. So far I have swapped plugs & coils around, installed new power pack, checked timer base resistance (within CDI specs), checked stator resistance and output (within CDI Specs), disconnected rectifier, disconnected kill wire to power pack. I have visually inspected the stator & timer base & flywheel magnets all seem to be OK. But problem persists. As I said this is an intermittent problem on the flushette and on the water. On the water as I throttle up to WOT she gets to 4000rpm with no power, then after a few minutes it just takes off revs to 6000rpm heaps of power and will run like that until I stop and restart. I always know when the lack of power will occur as it wont idle in the water after a restart. Sometimes it will restart idle great and run at WOT without a problem.
I can induce the fault on the muffs by pulling no 2 lead and putting it back on. I ran the motor (on the muffs) with the kill wire disconnected from the power pack, induced the fault, and noticed that when I pulled no 1 lead as the spark was jumping to No1 plug, No2 cylinder started firing, revs jumped up from 800 to 1200rpm.
I have run out of ideas and need some help, please. Problem now seems to be happening more often and I have lost confidence in heading out on the water.

 

[oldcatamount]

Re: 1980 70hp Evinrude no2 cyl no spark

Wow, tough question. It seems that you have checked everything you can. I'd look for a bad plug wire or connection on #2 plug.

 

[Joe Reeves]

Re: 1980 70hp Evinrude no2 cyl no spark

If when "switching" the coils around, the coil that didn't fire originally would now fire... then that obviously proves that the coil is okay. If so, you've pretty well covered all the bases.

However, check all of the PINS and SOCKETS within the rubber conectors. The pins and sockets have been known to back out slightly which results in a poor connection. Also the wires that attach to the pins and sockets have been known to break BUT still have the inner wire barely touching the pin/socket.

The wire appears to be attached securely as the insulation is still held firmly by the tight fitting rubber socket. In either case, the end result is erratic, weak, or no ignition/spark, a intermitent ignition problem that will drive one nuts if one isn't aware of this condition.

Let us know what you find.

 

[FUL_005]

Re: 1980 70hp Evinrude no2 cyl no spark

Plug wire is built into coil, so swapping coil moves plug wire. One thing I realised I havent done is a check spark jump test to see if spark is weak across all cylinders and winks in and out on No2.
Will check that next.

 

[FUL_005]

Re: 1980 70hp Evinrude no2 cyl no spark

Thanks, I think that is a good idea, I will check sockets particularly as all pins are pretty much new with the new power pack.

 

[FUL_005]

Re: 1980 70hp Evinrude no2 cyl no spark

Update, problem appears to be fixed. Fished today and she performed like a dream. What was it? When I said I swapped plugs, I swapped them around on the motor. Put in new plugs, correctly gapped and bingo! I think there is a lesson in this, don't go looking for zebras when you see hoof prints. First thing anyone should do when starting a troubleshooting exercise, bang in new plugs gapped as per manufacturers spec then proceed from there.
Thanks for advice, thought I would post an outcome as many don't.