My dad's eiger 400 auto is running really sadly. It has less acceleration than my ds250 now, i thought that it was because the reare tires were almost bald, but when i put it in 4wd it still didnt pull hard. When it was brand new you could feel it pull hard and it could kind of "throw" you backwards when you pinned it, now it has hardly any acceleration. Also, it doesnt run well with the choke disengaged. You have to have the choke on 1/3 of the way in order for it not to shut off when idling, and the ide spped is right incase you were wondering.

does anyone have any suggestions, i think the cvt belt might be worn out, but it might not be gettng enough fuel of the jetting is VERY lean. Does anyone know where i can find a downloadable manual for the eiger. not an operators manual but kind of like a manufacturers manual, one that shows how everything is put together.

 

Sounds like you have junk in the main jet. Take off the carb and clean it throughly. Let us know if that helps