dwheeler42,

I'm flying a Really oil soaked and heavily repaired Solo Sport with an OS 40 LA (not on floats) which weighs almost 7 LBS for our clubs instruction plane. I mention that to say that your 42 will fly the plane on floats if everything is set up right (and you use 15% or more). But, I think you will have a lot more fun with the TT.46. I highly doubt you will need anything larger than the TT46. If you want to do aerobatics as you said, then definitely put the .46 in the plane. I have a friend with a very seasoned Aerostar on floats and he always used a .40 FP (similar to the .42). It worked pretty good, but he always was leaning the mixture to the limit and the eng. would get hot, sometimes overheating. This summer he put a TT46 on it and he had a blast. Nice combo.

Jeff

Edit reason: Flying Solo Sport on .40 LA not .46 LA as earlier noted.