idle problem

I have a volva penta 3.0 sx. The boat is new and I only have 4 hours on the motor. I noticed the first time out it was shifting hard and figured out that the idle speed was at 1100 rpm which the manual indicated was too high. It is supposed to be below 800 rpm. I turned down the idle speed and that fixed the shift problem. However, now I am finding that when I first start the boat the idle speed is too low so then I increase it and then when it warms up the idle speed increases and I have to turn it down. I was wondering if it would settle down as the engine breaks in or is their a problem with the carb. Any thoughts? The dealer is an hour away and if possible I would like to avoid heading over there until the 20 hour check but if I have to then I have to.