ORIGINAL: planebuilder66
No, don't buy a new TT.46, go get a magnum,os or better yet, a supertigre 51. I have a TT42, not the same animal, but it took a while to get it right, it seems that the TT's have no mercy for lean runs, mine was almost cooked and lost due to my low tank position in the pulse xt.
A new TT 46 is a great engine, much better than my magnum 46. If he has tuning problems, the bad carbs on supertigres won't help him out at all. A low tank wouldn't cause a lean condition, you can fix all that with the correct tuning of the HSN.