HELP!
I have a 1996 225 Mercury EFI that recently lost 600 or so rpms and 10 miles per hour. It began as an intermittent problem with some sputtering, then became constant. I took it into an authorized Merc dealer and Mechanic who replaced my stator. This did not fix my problem, I brought it back. Then they replaced the engine wiring harnass saying it was bad, still runs the same. Then they replaced all of my coils, still runs bad. The motor used to run at 5800 rpms, and get 55 mph. Now only getting 5300 rpms and 45 mph...Any ideas out there? Now they are telling my it "may" be my cpu? What the heck?
I thought it might be a fuel issue so I had my tank drained, all hoses replaced, new filters, and filled with non-ethenol fuel, still not running right. Compression is good, new plugs, new wires and boots.....Any help or suggestions would be GREATLY appreciated.
FRUSTRATED IN MIAMI
Tony McInerney

I would be suspect of a broken reed.
600 RPMs is 1 cylinder down at WOT.
Try running the motor with 1 plug wire off at a time and see if you can find 1 cylinder that isn't playing.
Find another dealer

I WOULD find another mechanic, but they kinda have my boat hostage...I have already paid them for a new stator, which I don't think I needed. I havent paid them for all the other parts changing "yet" but I am hoping they will work with me. They have had the boat 8 weeks so far...

Bring it to the Keys I'll make it run...