Q. My 04 Briggs 21 HP started up fine. I made several passes through the yard and the unit shut down. I found that the fuel switch and 1 coil shorted out from mice, so I replaced coil and fuel switch along with the wires. Now the unit starts and floods out. I can see fuel in the intake, so I shut unit down and the engine speeds up and dies since fuel switch is working. I replaced seals and float body along with new needle valve, and with the bowl off I can see fuel turn on and off by finger movement of float but unit will flood out when started. I shook carb and can hear the float moving. Then I removed float and tested it on a clear bowl and float will move in fuel. Do you have any idea why it floods out?
A. While it is difficult to diagnose a carburetor problem on your Briggs 21 HP lawn mower without seeing it there are a few things you can check for:
- Is there any fluid inside of the float? If the float is cracked, fluid may seep inside.
- Check the seat, is the float is sitting correctly?
- Is there any debris in the float bowl? Sediment can get sucked up into the carburetor causing blockage.
- Check the atmospheric vent for blockage If these do not solve the flooding, you might want to consider a new carburetor for your Briggs lawn mower.
