1985 DT40 Wont stay running

i have an 85 DT 40. It will start but wont stay running. I tore the carb apart today and cleaned everything, put new fuel/water filter on cleaned the inline filter assembly screen, new plugs. I took it out and it ran good for about 30 minutes once i throttled back to idle it died and would not stay running again. almost like its flooded. Could this be water in my fuel? the tank has been full since last year and i put stabilizer in it?

I ordered a new carb rebuild kit and float today see if that helps

Any ideas would be helpful

Thanks in advance

Fresh Gas was the answer.

I pumped out the gas i bought at the automotive gas station that was over a year old. Replaced with fresh Marine fuel. Boat runs great.