My 1996 200hp Evinrude has developed an apparent misfire that only occurs intermittently. The engine starts and usually runs fine. However, on my last trip out while running on plane at 4200 rpm it seemed as if the engine would lose power on one cylinder for a few minutes & then the the problem would go away. When the misfire occurs, the engine rpm's drop 500-600 rpm and the fuel usage rate goes up by about 50%. During the misfire condition I can increase the throttle to pick up the lost rpm's, but when the misfire stops, the rpm's jump. This misfire condition occurred 4 separate times on he last trip. We had the same problem about a year ago & that time it just went away. It has ran fine till now. Does anyone have any suggestions as to what may be causing the problem?
