Mercury 225 CXL EFI 2004

by Allen B
(Long Island South shore NY)

I have 2004 twin 225 EFI with 740 hours on 94 Intrepid 268 with old controls and gauges not sure if 94 or 2004 plus wiring behind dash is very sloppy Changed 1 bad coil and 6 spark plug wires and plugs On port motor Port motor runs 100% according to Tech mate then after approx
40 min it cuts rpms down to 2500 Codes do not say anything bad And no horns beeps or red light Clear codes and runs fine for 40 min again and then back to 2500 rpm Does it both after 40 min one trip or 40 min combined separate trips Any help would be greatly appreciated Tank you very much