I have a mid 70s 70hp Evinrude 3 cylinder. I took the boat on trade about 3 years ago. The boat has always ran fairly well but not perfect. The 2 issues I had were #1 it would surge a little at close to WOT maybe 90% and above. That wasn't a big deal and there really wasn't much gain at that point anyways. I figured it was carbs needing some jetting but for what I used it for wasn't an issue. #2 Taking off or just very slow idle cruising sometimes would want to die. Normally I could touch the choke and clear up and be fine. Again I felt it was carbs needing some work but its a boat i normally just use to hunt off of and it always started great and got me where I needed to go. About a month ago I took it out with the family to swim some and such and the conditions seemed to have gotten worse. The surging was worse and it was probably at 60% throttle now instead of close to wide open. It was also harder to get to take off without dying. I assumed since it had bee 3-4 months since I had ran it the carbs needed a good rebuild but wanted to check my compression numbers first. My readings were top cylinder 105, middle 90, and bottom 100. I started the motor and let it run for a couple minutes and the #s really didn't change.
On a side note about this time last year I had a wire short out and burn up my complete harness. It also messed up my trim motor. I've since replaced the harness. I don't think this has anything to do with it but thought I would include it. At this point I'm just trying to weight my options on what to do. If the compression #s are too low I can have it bored out and freshened up. i have a machine shop who does good work at a fair price. But seeing I already have to replace the trim motor I'm jut wondering if by the time I gt everything fixed I could have bought a better motor.
On a side note about this time last year I had a wire short out and burn up my complete harness. It also messed up my trim motor. I've since replaced the harness. I don't think this has anything to do with it but thought I would include it. At this point I'm just trying to weight my options on what to do. If the compression #s are too low I can have it bored out and freshened up. i have a machine shop who does good work at a fair price. But seeing I already have to replace the trim motor I'm jut wondering if by the time I gt everything fixed I could have bought a better motor.