I had to become very proficient at rebuilding small 2-cycle carburetors. Thin film gaskets, fuel lines get eaten up and small fuel inlets and vias get clogged. So got the tools to help rebuild them and got to be able to find carb kits for all of my stuff.
I finally found on Amazon where I can get a whole replacement carburetor for under $15.....beats buying a new trimmer every year.
Living in Florida, you should buy a case of SEA FOAM off Amazon and dose your tanks with it following instructions while you’re using it. When you put it up for the winter, empty out the tank and run it dry until it quits.
On the chipper shredder, that’s likely 4 cycle....you could rebuild the carburetor pretty cheaply.
Thanks much :)