Was out on the lake to and was running fine then lost power. I have an 89 Evinrude 88 spl. On the the way back to the dock it felt like it wanted to gain the power back. I started to pull the plug wires one at a time to check for stalling. Only on two of the wires would it stall. Its still starts right up. Also I noticed that the tach would intermitinly stop working. I know I didn't over rev the engine. But could electrial problem cause a lose of power or am I looking at pistons and rings?