can say first thing id look into is a new air filter, always good to have fresh ones, glow plug(s), id grab a few, new fuel hose, imo id crack the diffs and make sure everything is as it should and re-lube.
were you given any indication on how long it sat? if its been a month or longer, id take the motor out and remove the carb and clean it. toothbrush and soapy water works wonders. take out all the needles, inspect and clean, wouldnt be a bad idea to replace o-rings.
pop the backplate off and clean that, old nitro fuel works well to break down the gummed fuel in the engine. personally id remove the piston sleeve, flywheel and clutches and pop the crank out to clean further in, but not necessary typically. clean the one way bearing(s).
then make sure everything is rinsed off and dry and re-assemble. while you are re-assembling id also through a small bead of sealant around the backplate, (bit of controversy on sealing engines, but unless you add to much it can't hurt.)
pre lube the carb a bit with fuel and put a few drops on the cylinder walls and on the cylinder and spin it a few times by hand to soak the fuel/oils into the sleeve, never want dry metal on dry metal.
then set back to factory needle settings and tune it in.
also id recommend getting a 5 cell receiver pack if it still has the 4 AA alkaline battery holder thing.
good luck!