So this Briggs 6.75 is on a toro personal pace. Starts on first pull but blueish whit smoke from muffler and runs ruff for maybe a minute then smooths out and no smoke. Mows good. If you stop and wait a few minutes starts right up and no smoke. Neighbor says it has been doing this for a couple weeks and has been smoking a little longer the last couple times. I cleaned the carb, changed oil ( did not appear to have gas in the oil), fresh non ethanol gas used and a newer spark plug. Any thoughts on what to check next?
Thanks