Air bubbles in the fuel lines

Replace the primer bulb.

Hi Lauren the easiest way to Blead these systems is to suck the fuel through the return line at the filter. This pulls all the fuel and air through the high pressure pump and primes the injectors. This is the most efficient way to do the job. Because even a small amount of air in the high pressure pump will prevent it from starting.

overhaul the carby
check /replace any fuel lines that are hard

sounds like you have a crack in one of the lines somewhere check them all and the bulb too..

CK for split fuel lines. You can ck when fuel is low by trying to prime with bulb, if you see air bubbles in line , split line in tank.

air bubble while you prime the bulb is normal

dont flood the carby

try a new plug

Open the fuel supply line into a container while it's pumping (running) and trying to start. When the fuel begins to run clear (no bubbles), then close the fuel line and it will light if all is in order.

It runs off the fuel from the priming cycle, so no fuel from impulse air/diaphram. Check impulse air line is properly connected, not cracked (leakin), else diaphram may need replaced (carb rebuild kit).

Sounds like you have an air leak. Either in the primer bulb is split or punctured, hole or leaking fuel line or primer bulb base, and is sucking air instead of fuel.

it sounds like the filter on the fule line is cloged try to remove the filter and then try to prime the trimmer. it it does you need to replace the filter. just about any filter that will fit will do.