My bike have been sitting for the winter when I went to start it would start run as long as I give it gas without it it would shut off and won't start. This weekend I removed the tank cleaned it out good and put fresh gas in it. Got it started ran about the same amount of time then shut off. I put a cap of marvel in the tank waited 20 min. the back started just could get it to catch the choke so I could adjust the idle. I had to give it gas to keep it running. When I let up off the gas it shut off but this time I was able to restart it. It ran longer with the restart was able to put it into gear and ride it around in my court for about 15min. Come to a stop and it shut off and would not start. Waited 20min came back and it started but just puttered even with the throttle wide open like it wasn't getting any gas. I would like to know could it be one of the following
1. one of the spark plugs
2. gas filter
3. Low oil ( Have not checked yet )

I think my carbs should be OK.. but I take it that one could be clogged up.
I would start it here and there during the winter so Im taking that its not the carbs.