I have had Stilhls all my life with minimal problems. I bought my first Husqvarna 450 rancher and used it thru the last year. Now, the prime bulb depresses but won't pull fuel even with the fuel filter off. Most fuel run thru it was canned Husqvarna fuel. It sat for about a month with pump gas with Stabil. I ran it after it sat and now won't prime/run. Any help appreciated thanks.
'Most' of the gas you say. It only takes one bad tank to ruin the fuel system. Ethanol increases octane. Nefarious fuel distributors will add ethanol to bad gas to get the ethanol up. That gas may have water in it, or be caustic to 2hstroke fuel systems. The practice is akin to butchers that soak bad brown meat in chemicals to turn it red so it will sell. I had to rebuild every small engine I had one year due to bad gas, from chainsaw to my riding mower. I pumped the same gas from the same no name station in my pickup and it took out the fuel pump
Also, E10 has too much water in it. But some stations pump E15, and it's much worse. You have to read the label on the pumps nowadays to ensure you don't pump E15 in older vehicles.
Try dumping all the water out of the saw's tank into a clean clear container, let it a few minutes, then look for water. It only takes a few drops to foul the carb.
Then flush tank with fresh newly mixed fuel. Remove return line from carb and pump primer button to flush out all old gas and water. Reconnect line and try to start and run the saw. If this doesn't help, the carb needs rebuilt or replaced (likely) and the lines need to be flushed before attaching to the new or rebuilt carb. You can buy a new carb online for around $20.
Saw shops have mountains of saws with the same problem stacked up every spring. My local saw shop closed down 2 years ago. He'd had enough. He'd fix something, the customer would add the same gas from their tank at home, their equipment wouldn't run long, then they'd return and blame him and demand that he fix it again for free.