Hello, I'm looking for some assistance in diagnosing an issue I'm having with my Mercury 175 Sportjet. I'm experiencing a "miss" underload around 1500 RPM and at 5000 RPM, Have used an inline spark tester and at idle I get a good spark, lose spark around 1500 and at high rpm's on I believe #1 cylinder . It is always #1 cylinder and ONLY #1 cylinder. I've switched coils, exchanged spark plugs, switched spark plug wires. I was wondering if it could be the ECU or switchbox? TIA
