It just doesn't run right-200 Merc

[bcmarinamanager]

i love my 200hp Merc. It's a '92 and I had a very similar problem running over 4000 rpm. My prob was the fuelpump though. sounded like it was doing the exact same thing yours was. Mine also runs kinda rough at the lower rpm range, not so much at trolling speed, but mid range, it sounds like it want s to run on out, and then cut back. can't find anyhting wrong with though. i just run with it. By the way, you definitely need to ditch the oil injection. Much Much safer.