1977 85 HP Evinrude

[Chad25]

Been trying to get this figured out with no luck. Motor quit running last year, out of the blue, just quit. Did some self diagnostics, and believed that the stator was bad. Bought a parts motor, and pulled stator from it. Did not fix the problem. So i tested the old stator off of the motor in a bench test, and it tested good, as well as the one off of the parts motor. So I checked the rectifier from both, and they were good. Tested coils and they were good. Swapped power packs out, and motor started running, but was real sluggish. Purchased carb rebulid kits, and rebuilt carbs. (took them apart, soaked them for several hours in Berryman Chem Dip, cleaned, blew out with air, used torch tip cleaners in every hole I could get them in, and reassembled). Motor started better than ever at the house with the muffs on. Took to lake, and wouldn't even start.( fuel boiling out of bottom carb). Took carbs back apart and adjusted the floats. Boat ran better than ever. Took to the lake, and when I got out of the no wake zone and hammered it, I thought heck yeah I fixed it. Then after about 5 seconds it fell on its face. I jacked with it and jacked with it until I was blue in the face. 1 and 2 plugs looked good. 3 and 4 were pretty gummed up. (and I had just replaced them). After about 45 minutes of it not running any better, it quit firing at all. With the spark tester, I could not see any spark.(The inline tester with a clear bowl). When I got back to the house and it got dark, I tried the tester again, and all I am getting is a very faint spark. Any suggestions as too what part may have failed? I have not done any electrical test since it quit running. Work out of town, so it will be this weekend before i will have a chance.