I have an 1975 Evinrude 85hp when at idle there seems to be a popping almost like one of the 4 cylinders is not getting good spark. I checked the compression and all 4 are at 115 lbs, checked the spark by pulling out the plug and watching as I pulled it away from the block, seems as if #2 cylinder is weaker than the rest. Is there an easy way to test the spark coming out of each coil. BTW the #1&3 coils have a crack in them...I guess they should be replaced, or sealed with some rtv. After speaking with the previous owner he said it idled fine but when he gave it gas (WOT) he said it lost power. I am thinking fuel pump any other thoughts??? This is a great forum and the info is great.
