There does not appear to be a primer bulb on the Stihl BR400 that I can see in the exploded parts.
You will probably have to go to the dealer. Stihl will not share Manuals or parts list with anyone but the dealer. You pay a lot for a Stihl and you continue paying as parts are not interchangeable with anything else.
A cracked primer bulb. You will need to replace it.
No gasoline is reaching the primer bulb.
primer bulb replacement on craftsman 32 cc week wacker
To change the primer bulb on a Snapper snowblower, first, ensure the engine is off and cool. Remove the screws or clips that secure the primer bulb assembly to the carburetor and carefully detach the old bulb. Install the new primer bulb by pushing it into the housing, ensuring a snug fit, and then reattach any screws or clips. Finally, test the bulb by pressing it to ensure it primes the carburetor properly.
Don't know that a leaking primer bulb can be repaired. Most likely, you have to replace it. You don't want to forget the routing of the fuel lines!! You might want to make a drawing of the routing before you remove the primer bulb.
There is an orifice in the primer assy. in the carb. that is plugged. You will have to remove and clean the primer assy.
The start primer rubber bulb must be cracked/damaged. Replacement parts are available.
It sucks gas from the gas tank to the carborator using nothing but suction In general the primer bulb draws fuel from the tank through the carb and then returns it to the tank. Look for "carb" and "tank" on the primer bulb and make the respective connection. A line should come from the tank to the carb. Another from the carb to the primer. and another back to the tank.
The fuel line routing for a primer bulb typically involves connecting the fuel line from the fuel tank to one side of the primer bulb, and then connecting another fuel line from the other side of the primer bulb to the carburetor. The primer bulb acts as a manual pump that helps to draw fuel from the tank into the carburetor to aid in starting the engine. It is important to ensure that the fuel lines are properly connected and free of any kinks or blockages to ensure proper fuel flow.
The carb connection on a primer bulb is typically located on the side of the bulb that connects to the carburetor's fuel intake. When the primer bulb is squeezed, it pushes fuel from the tank into the carburetor, helping to prime the engine for easier starting. The bulb usually has two connections: one for the fuel line from the tank and one that leads to the carburetor. Make sure to refer to your specific engine's manual for precise locations and configurations.
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