OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Brand new mower - major rich problem!

Be sure you put the diaphragm directly against the tank top, and the gasket on top of the diaphragm. Check that the diaphragm lays flat, no wrinkles, bumps or misalignment.

As Joe said, if you tried to run the old Pulsa-Jet without the air cleaner mounting screw in place, it ran vastly rich, but the Pulsa-Prime is a different animal.