I'm on my second 4 Star .40 , re kitted the first one and done a few mods to improve it's flight performance . Has a Saito .56 APC 11x7 and flys very nice. Most the time it's at 1/2 to 2/3 throttle , vertical is not unlimited but pretty close. I built mine as lite as I could and it still came out just under 6 lbs. I took out one bay inthe wings and stayed withone aileron servo to keepweight down. Added an inch to the rudder and 3/8 ofan inch to the elevator. Reinforced the fuse behind the wing saddleanda Sullivan tail wheel.
Ihave the CG set at the backof the main spar and it well hold a decent knife egde but still ,tucks to thebelly a little . Invertedis a lot of fun with thisplane and it's on it's back as much as wheels down.One thing I'm having trouble with is getting it to flat spin. Dropping a bay in each wing realy helped with the annoying balloning on landing . Always had problems with that . I have a set of floats for it, but have yet to try them. The 56. might be a little under powered for it ..
Really like the way it sips fuel , which I'm finding is a big plus , with the cost of Glow fuel today.
Enjoy your new engine, it's nice to have a good runner and that 46. should really haul the mail. lol