The return fuel line is loose or damaged. I have the same issue if you are talking the return fuel line. Here is a site I found a diagram on.
http://www.ereplacementparts.com/bolens-bl100-41bd100g965-gas-string-trimmer-parts-c-27272_27749_27758.html
No
Air bubbles in the fuel lines of a weed eater can be caused by several factors, including a loose or damaged fuel line, a faulty fuel cap that isn't sealing properly, or a clogged fuel filter. Additionally, if the fuel is low or the weed eater is tilted at an angle, it may disrupt the flow of fuel, allowing air to enter the lines. Regular maintenance and inspection can help prevent these issues from occurring.
The fuel line will come from the gas tank and go up the engine.The fuel line goes into the tank.
Restricted fuel return line or a faulty fuel pressure regulator.
"C" an overheated fuel line.
Lack of fuel. Either the tank is empty, or the line from the tank to the filter is clogged.
posseble because the fuel pump will suck air when fuel slashes witch causes air in fuel line . when air in the line reches the throttle body the sensers that control the fuel injecton sence a problem and there for sending a signal to the computer and finaly Check engine light comes on hope i was some help Kyle
You need a fuel line disconnect tool. Slide it over fuel line and push towards the connection and pull, the line will come off.
Age.
For the Ryobi 780R, the fuel lines typically connect as follows: the larger line is the fuel supply line, which runs from the fuel tank to the carburetor, while the smaller line is the return line, if applicable. Ensure that the supply line is securely attached to the carburetor's intake port, and the return line, if present, connects to the designated port on the carburetor or back to the tank. It's important to check the manufacturer’s manual for specific diagrams and instructions to ensure proper connections.
it may have a blockage in the fuel line, check every part of it form tank to engine.
Many possible causes: vacuum leak, clogged fuel filter or line, injector problem(s), faulty fuel pump.