In my prp raptor, sometimes i found my filter in the tank is out of place and it make it run a little lean, so I just open the lid and try to put it in place. When I still have the original engine, I notice that the carb it went sticky, what i just do is apply some after run oil in it most after using the truck, even right now with a diff engine in it.
Some few thing as an advice on your raptor. check that front and rear diff. as it alway fall apart on mine, better to replace those tap screw with a fine tread screw, I used stainless type screw. Some of the plastic are so brittle unless you got the truck that was been upgrade those plastic parts already, just boil those plastic parts for about 20 min.