First time on forum. I have a 2002 60hp 4 Stroke Merc. At idle, cyl #4 indicates low voltage due to weak spark when pulling a plug wire. Cyl's 1-3 show nice hot spark when pulling their plug wires. Replaced with new plugs and still had same problem. Spark does seem to be better (more even) when running at higher RPM. Can't swap plug wires as they are molded into coils. Motor has approximately 40 hours total run time. Gas is fresh premium grade. Any help is greatly appreciated.
Thanks

Sorry everyone. First time on any forum. Not sure how I ended up with multiple threads. Can't find any way to delete the extras. Any advice is appreciated.
Thanks