I have a 5 year old Craftsman mower with a Briggs & Stratton 6.0 that recently started acting up. It fires and starts when I prime it but I have to keep priming (one hand on the kill lever, one hand on the priming pump) to keep it running. This past Spring it had a similar problem but if I kept priming it for about 20 secs while it was running then it would "warm up" and stay running. This only happened the first few times I used it and then it was fine all summer until now. I took the carb off and the bowl off and cleaned it all up but no luck. I also replaced the fuel line since it had some cracks on the outer lining. Any ideas on what to try next?

Should be a quantum? Well make sure the tanks cleaned out, it should have a mesh screen at the nipple, to filter and it gets clogged. Next would be to actually make sure all holes are blown out with cleaner in the carb? And next would be the gasket between the carb and the air cleaner box, this works with the primer and can leak.