The thing with pump gas is the ethanol, it absorbs water. That is why I buy ethanol free gas for the mower, tiller and the 2 cycle power tools. I use Seafoam mixed following the directions on the can of 1 oz per gallon of gas in the first gas of the season to clear out the carb even though I drain the tanks and carb each fall. Seafoam does stabilize the gas and so does the Echo 2 cycle oil I use in the two cycle gas.
On the pressure washer front since my use will be only every 3 or four years I will rent instead of buying.
George
Making sawdust regularly, occasionally a project is completed.