Hi. My lawnmower is starting up and then gradually dying after a few seconds. It is not sputtering or difficult to start. I used the lawnmower 8 days ago for well over an hour, so I am guessing it is not bad gas or oil, but I have not tried replacing those yet. This mower has had a history of issues starting, but in the past, when I took apart the carburetor and put it back together again, the issue was fixed. This could be related. Any help would be great. Ben