During operational months do as we (most/many) do... use an inline fuel filter (I change em yearly), drain the float bowls occasionally to check for water/debris. use (your choice of Seafoam/Stabile/Startron, etc. (many others) to keep the bad ethanol "gas" at bay, ; I also follow Randaaks rec of Marvel Mystery Oil to protect the fuel tank and lube the carbs in-situ.
I can't think of any others, but they all seem to revolve around moisture, debris, or fuel contamination. Makes me yearn for the days of 100% gas...
The good news,== once you start with good clean carbs, this regime (for me) has worked well.