2003 Mercury optimax ran great as twins, doesn't run correctly as a single engine.

[wpowell323]

I have a pair of 2003 150 optimax motors. They came off a 2004 whaler and were on the boat with smart craft gauges. Both motors ran fine when they were removed. I recently installed the counter rotated motor on a project boat and I have all sorts of crazy codes. I didn't hook the smart craft back up, I just used regular gauges. My question is are the motors linked in anyway? I would think each motor works indepndent of the other, but does the counter motor know if they are linked or unlinked? Does the smart craft have to be hooked up to work correctly? The Only thing weird is see if 2 plugs. Both about 2"X1" where the smartcraft hooked up. The 2 plugs seem to be the same on the motor have different color wires. One has red, black, purple, gray and maybe brown? the other has various white wires with tracers. I swapped the computers, but still had the same codes and all sorts of weird readings. The motor cranks and runs and idles, but that is it. The codes are Port, starboard and compressor temp codes. Port and starboard show 32 degrees and compressor shows like -52, the tps shows 100% at idle. Engine load is 70% at idle. If you clear codes they won't clear and immediately come back. The tps reads in reverse. if you push it wide open it shows 0 and closed shows 100. there is no in between. I have the diacom system so I can read codes and such, but I am at a loss on this one.

2003 mercury optimax 150 cxl
serial number 0T631363