My original primer bulb was 15 years old and finally sprung a leak. You might try running the hose and bulb to a can of gas (lots of things can go bad with can of gas, be careful) and see if the motor will fill and firm up the bulb. If i get around to it any time soon ill let ya know the results. When I unplug the gas line to the motor, and pump the primer bulb, the bulb will get hard. Get it as soon as Fri, Jan 8. and Washington Guides | Gasoline in a small outboard flows from the tank, through the fuel line and primer bulb into the engine fitting, through a fuel filter, to the fuel pump, to the carburetor. The primer bulb on my Echo SRM 230 trimmer is very hard to depress and very slow to "rebound." I suspect your fuel pump is not set up correctly (easy to goof up--don't ask!) I tried poking the bearing and seeing if i was getting any fuel, nothing. Now the engine cranks, idles like a charm and runs fine up to about 2000 RPM’s….. beyond that it simply is not getting the gas it needs. Outboard primer bulbs - Duration: 5:24. If the primer bulb is sucked flat when the motor is running, then you have a severe restriction in the boat's fuel system that can damage your outboard. I changed the bulb and still no luck so I changed the hose as well. 4.4 out of 5 stars 293. Then, stick your finger on the hose barb. Primer bulbs do not work well if there is lots of air and no fuel.