I had the same problem with a 1985 evenrude 70 hp I put in a new Power Pac cleaned all 3 carbs with new kits and still had the same problem I finally talked to the guy I got the motor from and he said he had the same problem he finally gave up and bought a new 115. I finally learned that if I pushed in on the key while applying throttle I could get over that spot and it would run great. I may or may not have that problem again that day but if I did pushing in on the key and giving more throttle worked.