final advice on power pack exchange?

[richardbrown67@yahoo.com]

Thanks to this forum I'm moving ahead.

Expert, humor me if you will....

Here are the facts:

1980 Johnson 70hp 3 cyl.

Starts easily, runs well for 10-15 mins, then bogs down and finally quits

No spark on #3 cyl after motor misbehaved. Spark good on 1 & 2.

Swapped coil wires #3 with #2.

After the swap, #2 cyl had no spark, while 1 & 3 had good spark. A-ha moment.

Swapped coil wires back to original configuration - again, no spark on #3, spark good on 1 and 2, as before.

SO - I think all three coils are okay. A local mechanic told me it is very likely that the problem is a faulty power pack, but it could be a faulty timer base.

All the electrical components look original, so they're 30 years old.

I put in new spark plugs, L77Jc4, according to a manual.

So - at this point - if it were you -- would you install a new power pack in hopes of solving the problem, or are there other steps to take? What about the timer-base?

Thanks, everyone.

Richard

 

[Sixmark]

Re: final advice on power pack exchange?

OK, you swapped the coil wires and then you had spark on #3.........then returned them to original configuration and lost spark on #3 again, this would tell me that you have either a bad wire or a bad coil.


As it was stated many times before, swap the coil pack with one from another cylinder if the no spark condition follows the pack you suspect of being bad then you have your answer.......replace the coil pack.

 

[jonesg]

Re: final advice on power pack exchange?

Do all the coils, new plugs wires too.

 

[the machinist]

Re: final advice on power pack exchange?

I had about the same problem on my 1980 70hp also. However mine was no fire on #3 until the motor warmed up. And then finally nothing on #3. I finally isolated it that everything pointed to the powerpack. Changed that with a new one & runs fine now.

 

[Sixmark]

Re: final advice on power pack exchange?

Jones is actually telling you the right thing to do, if I have one coil go bad I usually replace all 3 and keep the others for emergency spares.

Coils are not that terribly expensive anyhow, I can get all 3 for $65.

You can end up spending that much on dinner for two at the local resort after a good day of boating anyhow.