I have a Kraftsmann 550 series push lawn mower with Brigg and Stratton engine that runs for about 10 minutes and then sputters and dies. I can start it again after prime it again, but it will run for less than 10 minutes and then dies again. each time I restart it, it will run for shorter time. here is what I have done 1. cleaned the carburetor, cleaned fuel tank 2. replaced diaphragm 3. replaced spark plug 4. replace the blade 5. tried loosing fuel tank cap when it starts to sputter
but non of the above seemed to help.
what else could I still do? thanks for your help