hi vin 209,

with the info ex-nitro gave you, you could open the graph editor under WINDOW/ANIMATION.
Select you fan, or the object that is rotated. Now you should see one or many curves, depending on how many attributes you have keyframed. On the left side click on the attribute you want to focus on. I your case rot. x, y, or z. Now you see the corrosponding curve, with your keyframes displayed as black dots.
The x -bar of the graph editor displays time and the y-bar the amount (like rotation, or position.)
If you select one of your keyframes two handle will apear. If you push and pull them your curve will react accordingly. That's how you can "fine tune" your animation. You can add keyframes, delete move them around. I can't explain all the buttons inthe graph editor, but if you play a little with the handles and the basic functions it has I am sure you can fix your problem. Check the maya help as well, it explains the graph editor quite well.

I hope it helps.