No same fill hole for both i got some regular formula 1 atv oil for mine at walmart.I try to stay away from anything synthetic but that's a preference thing i think.diesel 15w40 works well too as long as it doesnt say engine conserving! It has some crap in it that makes your clutch slip.
Another Rotella 15w40 user here, with the engines primary cooling being air a diesel oil at that weight is perfectly fine! Not to mention if your anal about changing your oil alot, it wont break the bank.