1970/71 60 hp Johnson - Bad Amplifier or Coil?

[The Grail]

I could never find a model number but it is either a 1970 or 1971 60 hp Johnson with Hydro-electric shift. After it stopped running the other day, I found that it was not getting spark to any of the plugs. I read a lot of related posts here, but I still need more info.

I did F_R's test of removing the coil wire from the distributor, creating a spark gap to ground with coil wire, and grounding the amplifier-to-distributor wire with key on. No spark at coil wire, but I did hear a slight clicking (once per grounding) that sounded like it was coming from the amplifier.

The three wires as they come out of the amplifier are corroded almost through, and I did my best to splice new wires and ran them to the terminal board. None of these wires are purple - they are tan, light green, and dark green. Tried the test again with a spare coil (no idea if spare is good) and got no spark again.

I'm getting good voltage from key switch to terminal board at amplifier connection, and the battery is 12.55 volts, 11+ when cranking. When it stops raining, I plan on trying Joe Reeves' "Battery Capacitance Discharge Powerpack Test". If that fails, does it mean that amplifier is bad?

How can I test coil to see if it is the problem?

Thanks.

 

[R.Johnson]

Re: 1970/71 60 hp Johnson - Bad Amplifier or Coil?

Without a regular coil tester, a ohm meter is as close as you can get.

 

[F_R]

Re: 1970/71 60 hp Johnson - Bad Amplifier or Coil?

And even that is a pretty inconclusive test. It does not test for high voltage leaking.

 

[jumanjii1]

Re: 1970/71 60 hp Johnson - Bad Amplifier or Coil?

Looks like the Amplifier is shot. Even by your accounts of the wires being frayed, that should be enough to tell you it's time for a new one. I bet the Rectifier wires are also frayed so you might have to change it out as well.

I have the same motor and the same frayed wires on the Amplifier, Rectifier and Clipper module. Ripped them all out and just replaced the Amplifier and Rectifier. The Clipper Module is not needed and was just there to protect the sensitive Amplifier module in case of reverse polarity battery hookup, so I was told.
You might want to change out the coil as well. And while you're at it, check out the points under the Flywheel. Adjust or renew as needed.

Water pump??? Every 2 years or now if you just got it.

Good luck

 

[The Grail]

Re: 1970/71 60 hp Johnson - Bad Amplifier or Coil?

Thanks for the input, guys.

Well, it failed the power pack test - no flickering at all on the testlight. Afterwards, when I removed the assembly, I found that one of my wire splices was loose. I may try a last ditch repair on the wires and try it again, (ok, I know I will) but I'm guessing its a waste of time and hope. I'll keep an eye out for a used one as I the new ones aren't cheap. For a new one, it looks like CDI is the one to get. I saw $217 for an amplifier with a new coil, versus $377 for just the amplifier from my local Johnson dealer.

If anyone has successfully converted to an automobile setup, please let me know.

Thanks.

 

[F_R]

Re: 1970/71 60 hp Johnson - Bad Amplifier or Coil?

Looks like the Amplifier is shot. Even by your accounts of the wires being frayed, that should be enough to tell you it's time for a new one. I bet the Rectifier wires are also frayed so you might have to change it out as well.

I have the same motor and the same frayed wires on the Amplifier, Rectifier and Clipper module. Ripped them all out and just replaced the Amplifier and Rectifier. The Clipper Module is not needed and was just there to protect the sensitive Amplifier module in case of reverse polarity battery hookup, so I was told.
You might want to change out the coil as well. And while you're at it, check out the points under the Flywheel. Adjust or renew as needed.

Water pump??? Every 2 years or now if you just got it.

Good luck

The clipper circuit is there to "clip" or limit voltage spikes which occur because of loose battery cables....or opening certain switches anywhere that creates a spark. I understand the feature is built into the new amplifiers. At least I hope it is.

 

[bigpoppakdog]

Re: 1970/71 60 hp Johnson - Bad Amplifier or Coil?

I have a bombardier pulse pack #398363 for my 1970 115 hp evinrude. It's an extra one due to previous owner buying one when he didn't need it. I'd sell it to you a lot cheaper than $200....not sure if it would work for that motor....