How much seafoam have you guy's been adding per gallon? I have a riding mower that had water in the gas tank. I drained it, blew it out, but still think I have a little residual water plus the carb had a lot of crud in it. It will run ok for a while then start to die so I choke it hard a couple of times and it straightens up for a little bit. Just wondering what you have had the best luck with.