I have had the same problem with all my motors. Put in dry gas / seafoam and they are running better. I believe we are starting to see the results of ethanol in the gas. One motor I pulled the carb off and the inlet jet was plugged with some corrosion,whats so bad is that the carb was worked on 4 yrs ago and now its clogged again. So it looks like some sort of additive will have to go in my gas from now on.