Replace the ignition system on a 71 50HP Evinrude with a 74 50HP Evinrude/Johnson

[Kitakojo]

The question I have is can I replace/swap the entire ignition system on my 50173s 50HP Evinrude with the ignition system from a 74 50442M 50HP Evinrude? This would include the stator, power pack coil assy, and timer base assy. I noticed by doing a parts search the power pack, timer base assy, and stator has a different p/n and is not used from one year to the other refering to 71 & 74. The flywheel and coil assy are the same p/n. The motor cable on the 71 is yellow in color with more pin connectors and the 74 is red with less, but it looks like the motor cable connects to the terminal block. I notice the stator on the 71 is 6 amp but not sure what the 74 is amp wise. What would be the difference in the power pack sice they have different part numbers?

Like I said I have the entire ignition system off of a 74 and wondering if I can put this on the 71 50HP.
I had started another thread a few days ago titled 1 doggy 71 Evinrude with a tick. That will explain the issues I'm having and why I want to know if this will work.

I also noticed on the crankcase there is a safty switch assy. that has a electric wire ground) from it to the smaller terminal on the slnoid, was wondering if that is for the electric shift. Someone ran a seperate ground wire from the slnoid to motor ground. when I disconnected the added ground wire the motor would not crank so obviously the switch is bad. is this important or just a safety feature. And yes safety is important.

Please help maybe someone has done this or I'll be the first.

 

[lmuss53]

Re: Replace the ignition system on a 71 50HP Evinrude with a 74 50HP Evinrude/Johnson

The yellow plug power head is an electric shift motor. The extra switch is a neutral safety switch I think. I have a yellow plug mystery year powerhead on my 55, with manual shift. I can't tell you anything about whether or not your other parts can be swapped.

 

[Kitakojo]

Re: Replace the ignition system on a 71 50HP Evinrude with a 74 50HP Evinrude/Johnson

Yesterday I decided to do the ignition upgrade. I started with the stator and the timing base assy. Everything went together just fine, I used the old stop or linkage arm on the timer base assy. since the two were different. The stator harness had a ground wire which the original one did not so I connected that to the engine block. I upgraded the power pack and replaced the coils. Put it into the test tank and fired it up. It seemed to start right away with very little effort from the starter. I notice right away that the miss was gone and when I increased the rpms with the timing light connected to each one of the spark plug wires there was no hesitation or miss in the strob light.

Well you know I had to load the family up & head to the nearest lake for a test run which we did and wow what a difference a motor that would actually accelerate and plane the boat out. We spent about 2 hours cruising around which the kids loved. So to everyone whom helped thanks a million$$$$$$.