Are you sure the gas in the tank is good fresh gas that isn't contaminated?
Are you sure the choke is completely off (see if the knob has any freeplay, sometimes the choke plunger will stick and the choke stays on when you think it's off)
If you've ruled those out, could be a clogged petcock, clogged petcock screen, or a dirty carb. Could also be a clogged vent line on the gas tank, which creates a vacuum on the tank and doesn't allow fuel to flow well.
First thing to do is crank it up and if it starts to idle rough or dies, unscrew the gas cap and see what it does. If it still idles rough or dies, turn the petcock to reserve and see if that helps.
If none of those work, you'll have to pull the tank, remove the petcock, and try to blow it out with compressed air. If you do this, use an impact on the two 8mm bolts holding the petcock to the tank. Those bolts are screwed into metal inserts that are in a plastic tank, so a lot of times the insert will start spinning before the bolt breaks loose and you end up ruining the tank. If you have to take the petcock off use an impact to snap the bolts loose before the inserts spin in the plastic.
I use a 1/2" impact with a 3/8's adapater, and then a 1/4 adapter on the 3/8's so I can use the right 8mm socket for those petcock bolts.
2005 Foreman Rubicon Camo
Perfex, 27" Mudbugs
Heated grips and Thumb , HID's
5K Viper Max winch
2009 Foreman 500FM Green
Perfex with HL springs
27" Execs on Rubicon rims
Heated Grips and Thumb, HID's
4K Viper Max winch
2006 Foreman 500FM Green
28" Mugbugs, stretched, Perfex, HLsprings
3K Superwinch winch
2009 475 Rancher AT Tan
26" Mudbugs on Rincon rims
Warn winch. Foreman pod light with HID, SRA gear reduction