It's not unusual for the gen to use some oil. Mine has about 48 hours and is almost down to the add line. Make sure you are level and the cap is screwed all the way in when you check it.
I believe the manual says to change the oil every 75 hours or one year, whichever occurs first. I have not done mine yet since we had to leave on our current trip 2 weeks sooner than expected. You may find with your Sunseeker that you will have to move the exhaust pipe back about an inch or so to get access the the cover and you will need a star bit I think to remove the cover to get to the drain plug. I am sure somebody will correct me on this if I am wrong.
Here is a link to the manual. I tried to upload it but my internet connection at the campground is pretty bad.