IMHO I'll take a TT 91 FS Thunder Tiger anyday over a .61 FX. I love these engines and own two...heck I like them more than my YS 91 (value wise)! You can pick them up from Tower for around 164-169 delivered (179-(10-15) promo). You will not be disapointed in this motor. Search around on this forum and you will come to discover that the TT 91 FS has as big a sweet spot in many peoples heart as the Hog Bipe...and is truly a spot on match for that plane.

I had to add an ounce and a half to the tail and it still has unlimited vertical. I have actually hovered it a few times, but end up losing it into a torque roll due to the small ailerons.

I love doing knife loops with this bipe...oh and P.S. it will do the most incredibly power on flat spins and inverted spins you have ever seen...soooo flat. I can't get a climbing inverted as it wants to roll out of it....again possibly the size of the ailerons?

This is one bipe and engine combo made in heaven. A bipe that actually glides yet has enough power to go straight up and into a snap roll at take off...its too good to be true!

last, you will be amazed at how fast this bipe goes together. Faster than some .40 size monoplanes i have built.

Nick