j manikis,

Sorry to hear you are having trouble. I have a stock OS on mine too and it ran pretty well first time out. I set mine up as per the manual and it runs nice. I'm no expert by any means so all I can suggest is that you double check to make sure you have the outboard set up like the instructions describe. I have no weight in the nose as well. The only time I get any porpoising is if I'm going slow. Oh, and for now I have the stock prop on too, but that will be changing as soon as I have time to work on the 215 I have.

Good luck,
John