Why my Briggs and Stratton 4.5 HP lawn mower engine prime I have removed cleaned the carb. The primer worked properly before disassembly. Now bulb shoot fuel into carb?

There are a few possible reasons why your Briggs and Stratton 4.5 HP lawn mower engine might prime but shoot fuel into the carburetor instead of the engine:

Damaged primer: Inspect the primer bulb for any damage or cracks. If the bulb is damaged, it will not be able to create the necessary suction to draw fuel into the carburetor.

Clogged fuel line: Check the fuel line for any kinks or obstructions that may be preventing fuel from flowing into the carburetor.

Improperly seated carburetor: Ensure that the carburetor is properly seated and tightened against the engine block. If the carburetor is not seated correctly, it can cause fuel to leak out of the carburetor.

Damaged carburetor float: The carburetor float is responsible for regulating the fuel level in the carburetor. If the float is damaged or does not move freely, it can cause fuel to overflow and be pushed out of the carburetor.

Faulty fuel line connector: Check the fuel line connector for any damage or loose connections. A faulty connector can cause fuel to leak from the carburetor.