DF250 Idle RPM Issue

[DaWallach]

Good Morning All, I am new to the forum and just bought my boat last season. I am looking for some help/tips on correcting my idle RPMs on my 2004 DF250s.

1. What is the normal idle speed for these motors to be running at? (whats healthy)
2. I have my port idling at 400RPMs which feels very low and my starboard idling at just around 800rpms which feels high
3. Is it possible to tune these somehow? Do I need a mechanic to plug a computer in and change my idle settings or something like that?
   1. If not is there a part that could be problematic causing such low/high idle RPMs

One thing to note as well is that my port IAC went bad on me last season and I had to replace it, I didnt really notice a idle RPM diffrence from this change. Any help would be greatly appreciated!