I bought a new spark plug put it in I have spark but it wont start, also took the filter out and sprayed a little gas in carb and still wont run.

 

Has it been setting up for any length of time? If so it may take a good carb cleaning.Plus you can check fuel supply to the carb by pulling the fuel line at the carb and crank the engine over. If the pump is ok you should have a steady stream of fuel while it's cranking over. Spray a little starting fluid on the air filter and see if it will at least try to run on that.If it does then carb cleaning may be all that's needed.Plus 98 Sportsman 400? I guess you mean 500. Or do you have a 400 2 stroke? Big difference.