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!!