Myy father-inlaw recently left me with the above mentioned ATV after we moved to Kodiak, AK.  He removed all the gas and oil before shipping it up here and never filled it back up before he moved back to California.  I recently filled the gas tank and oil, and tried to get it running.  It started for about 10 minutes and stalled out.  I could not get it to turn over again, so I replaced the spark plug.  I also made sure we had a good spark.  It ran for another ten minutes after about 15 minutes of kick starting it.  I am wondering if there is a fuel filter I need to replace, or am I missing something simple.  Yes I turned on the gas, kill switch and choke.  When it does start the the choke is very touchy.  

if it is the old metal gas tank then chances are you could possibly have some rust in the tank.

i would take the carburetor off and clean it out and inspect it.

if it has a metal tank and it doesn't have a fuel filter on it, make sure you put one on it.