RE: Saito 100 in U Can Do and extended hovering
I have the Saito in a Fliton Extra 330 (AWESOME!!!) but before that the engine was in a Funtana40. I had constant issues with it in the Funtana. When I switched everything over to the Fliton I went the route of a Perry pump and a straight pipe. It was the best decision I ever made as the engine runs without a hicup from full tank to empty. Basicly any possibility of the engine leaning out as the tank runs out is eliminated.
I also agree with the cowl issue. I think the rule of thumb is the exit should be twice the size of the opening. And I don't think the opening of a UCD is big enough to start with.
Another thing I also suggest is changing props. I have never had great success with any of these ultra low pitch wide props and I have tried several on several different motor applications. I find that when you throttle out of a hover you just don't have enough punch. I am running a APC 15x6 and my Fliton weighs 6lbs 6oz and I am hovering less than half throttle and when I punch it it is ballistic! I really think the higher pitch will make a world of difference and if your plane weighs about the same the engine can definately handle the extra load.
Give it a shot.... I think between the cowl and the prop your problems will be solved and I am sold on Perry pumps. Running a straight pipe it sounds AWESOME! It's like a Harley in the air.
Good luck!
JP
PS I am running 30% heli