Had a Warrior a while back and it used to sputter sometimes, traced it to the wires and connections related to the reverse switch... I think, been awhile!

G

 

Check that rubber doohicky between the carb and the cylandar (i think it's called the intake manifold) it might be cracked. I bought mine with a small crack and i didn't know it and it ran funny all the time and one day it broke off and when i replaced it it ran soooo much better.