I have another suggestion. I just finished up a 1953 Evinrude 3 horse Lightwin that I installed a "new" tune up kit and two new coils. I got spark on one cylinder and not the other. What I discovered is that this "new" still in box OMC tune up kit (172522) had somehow glazed over the points and it was not making good contact. So what I did was remove the points, used an emery board and cleaned the point tips until they were no longer "shiny". I also cleaned the bottom of the point base where it makes contact with the mag plate. If the mag plate has oil or dirt, clean it as well. Lightly scrub it with emery paper or what ever you use, then clean with brake clean or carb cleaner, wipe off and see what happens. From now on, whenever I use an older OMC tune up kit, I am going to clean the points before I install them, just to make sure that a part that has been sitting around for 30 plus years is still usuable. I hope this gives you another idea of what your problem might be.

Always clean new points before installing!

First of all make sure your compression reading is correct. Assuming your gauge is accurate you will need to give about 3 pulls to get a final maximum reading. Might get about 95 on the first pull, then 110-115, then 125 on the last pull. Also must do it when the motor is cold and dry. Warm motor may give slightly false low readings. Adding oil or even flooded fuel can give a false high reading. If 95 PSI is truly the correct reading, you are in for a ring job, cylinder honing, etc. I have several extra 18 HP OMC powerheads with about 95-105 PSI that are on my list for rebuild. Not going to happen anytime soon though as I have plenty of good runners.