dnb55 here is the link for purchase.

http://www2.towerhobbies.com/cgi-bin...?&I=LXDG59&P=7

You will have to tap the crank case of the engine but its no biggie. What I did was to, and make sure you do this remove the rear crank case cover by removing the four allen head screws holding it in. Since the cover is thin metal I laid a thin layer of JB weld first, let it dry then I taped with the recommend tap set through both the JB weld and the plate, inserted the nipple provided and then added just a tab bit more JB weld around the nipple only.

The pump I mounted just behind the engine on the fuse just where the slop starts with a wood screw. To keep the pump from moving around in the plastic hold sleeve (also provided) I used RTV (silicone) to keep it in place.

One other thing I did was to replace the stock muffler with one from an older model Magnum in which gave me 400 more RPM, What I have seen others do with the stock muffler that comes with the 91FX is to remove the extending spacer which seems to help also.

With the pump setup this will also give you better throttle response when in a hover or 3D in general. Keeps a constant flow of fuel to the carb, hence engine inverted and at idle on the ground. One last thing I did for my configuration was to add a remote glow igniter, "NOT ONBOARD glow system" but a remote which allows you to apply a starter stick from another location on the plane.

http://www2.towerhobbies.com/cgi-bin...&I=LXBC35&P=ML