Looking for some advice on this one. I started my cockshutt 30 this morning and it started up great. Ran for about 2 minutes and then started acting like out of fuel or maybe coil or points issue? I just timed it last year in the fall and was running great. There was no fuel in the tank or carb at the end of the season. I don't believe it is a timing issue because it runs great for a limited time then acts up and sputters, backfires and stalls. It wants to run but struggles. I removed carb and everything looks good. Could it be a faulty coil? or any other suggestions. The plugs are fairly new but noticed two of the 4 have a bit more carbon build up. I cleaned them and same issue. This is the first time this has happened and ran great before storing for the winter.