I have a Bolens push mower with a Briggs & Stratton 500 series 158cc L head 4 stroke motor.
Last used it about a month ago and it started right up and ran great. Yesterday I pulled the starter cord and it would fire but then die after about 3 seconds.
Good spark, clean plug.
Dirty air filter. Cleaned it and tried it with and without it. No change.
Drained the gas and added new gas. No change.
Verified that at least when I push the primer bulb gas moves freely.
When I start it if I immediately start priming and keep doing it steadily it stays running. It revs up very quickly to its normal idle and rapidly starts to die and I can just hit the bulb again in time to have it rev up again before it dies.
I'm going to buy a tune-up kit today just in case but between good spark and still not running with the filter off and fuel able to move when I press the primer I have a feeling the kit isn't going to solve the problem. It seems like maybe a clogged jet. I have no problem opening a motor up and have all the tools but would like a good place to start on this one.