Hi on my u can do I have everything set up for a new .91 FX, (the other one somebody tightened the glow plug too much and stripped the head, and one i took the head off the cranckcase the liner was stuck too it; I already tryed to remove the liner with heat, then force, but that did nothing, plus, somehow the piston is scratched up pretty bad!! so it isn't worth rebuilding, because mine was a lemon to begin with[:@][:@].) So should I buy another .91 FX, because my u can do is already for it; because i have the cowl specially cut for it, and i also have a pump mounted to the engine mount!! Or should a buy a 4-STROKE or a 1.08 FSR? Thank You!!

I have not seen the new TT90pro but they usually have the same bolt patterns and such and darn near a clone tot he OS line up. I would choose that over the 91fx or go with the 61pro or 61fx, 61fx is a much better engine than the 91fx

You might consider the Magnum 91XLS. A friend has one e realy likes. I also have the Magnum carb with the front needle on my OS91fx - a good combination. The Magnum price is better than OS also same bolt and muffler pattern.

The OS 91FX doesn't even make a good paper weight, and it's not shaped well to be used as a door stop.

Find a fish to buy the OS, get a Magnum for the plane. A lot better engine, and less expensive to boot.

Bill.