I feel like replacing the points down the road might be a better and cheaper option than replacing the amplifier. The amplifier is $200+
.....and you will be lucky to find the points for much under $100- for a set....I think that is X 2 for that motor.
The basics of that ignition system are virtually the same as the 55 HP of that year. I know it intimately....and still have the scars to prove it.
If it were me and I had the opportunity to do it all again ....and avoid the scars....
.... I would either just run away....or proceed in this order:
1) Pay attention to F_R....he is bang on....
2) replace every original wire under the hood.....cleaning grounds and connections as you go ....meticulously. There are so many minor faults that can cause major issues and take out components that you need to be absolutely anal about it.
3) There have been a number of questions in here about these early CDI models and I shared a lot of my pain in responses. I am not going to retype all of it but it should be available in advanced searches using CDI issues, 55HP etc. I am not a Guru like a few of the posters in here, but did a major electrical refurb on a Johnson ~ 55 HP.... full new wiring harness....had to make it myself....all joints heat-shrunk...etc. This was after taking some shortcuts and blowing $400- worth of new electronics that had failed the first time, requiring the replacement. It is a bit like painting over badly prepared surfaces.....it never ends well.
The key is that there are no good shortcuts and that bad connections can fry really expensive components....that is just the nature of the system.
Before embarking on this if you choose, be sure to do the due diligence checks on compression etc.Make sure there are no hidden landmines.
This ignition refurb will be picky and time-consuming work, but will be well worth it.
I got 5 more years from the Johnson and it actually made it to 36 years service before I sold it for parts.....other things were wearing out....
And be careful of those points. Cleaning them with solvent is OK, but do not use an abrasive method. They are not high voltage conductors and are not subject to the typical pitting you get on "regular" points. There is a hardchrome type finish that makes them last almost indefinitely ...unless some bonehead goes at them with a points file ....then they tend to cause problems fairly soon , and I had to replace them a month or so after that bonehead had at them...but they were only $40- at that time.
