So far i have replaced the carburetor, ensured rubber hose from gas tank to carburetor is clear and clean. I also cleaned out fuel tank and added new premium gas, changed oil, replaced spark plug. It is getting spark. The only way to get the mower to run is spray starting fluid directly into the carburetor with air cleaner removed. It runs for 2-3 seconds. Cannot get it to keep running. The carb bowl is full of new clean gas. Please advise what else to do to get it running and keep running.