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Why My Primer Bulb Won’t Fill Up – 6 Savvy Solutions!

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The primer bulb is a small piece of equipment, but it is vital.

On a small modern engine, it might just appear to be another piece of plastic, but its purpose is to pull fuel from the reservoir and supply it directly to the carburetor.

These things occasionally tend to stop functioning altogether and make you wonder why my primer bulb won’t fill up. Fortunately, this article has the solutions for you. It contains excellent examples of tasks you may successfully perform while relaxing at home.

We’ll go over the entire process with you today!

Broken primer bulb—why my primer bulb wont fill up
Why my primer bulb won’t fill up? – Image via Reddit.

Why My Primer Bulb Won’t Fill Up? | How Can It Be Fixed?

Primer bulbs frequently encounter issues when the filling process abruptly ends.

If this situation persists, it may have several unanticipated consequences.

Therefore, it is advised to prepare ahead and be aware of all available options. This article will outline several techniques for identifying and resolving why my primer bulb won’t fill up.

If you have never repaired anything similar, don’t worry.

All that is required to solve this particular issue is the desire to learn and try. You won’t need to perform any advanced tasks.

That said, let’s go on to our first piece of advice.

1. An Air Leak Might Exist

If the bulb isn’t working correctly, this is probably the reason.

  • The most likely culprit for the problem is the leak in the intake line.
  • As an alternative, this might also occur if the intake line is of the wrong size.
  • It’s also not advised to bury the filter line with petrol in the tank.
  • Start by getting a cup of petrol and pouring that inside.

Depending on this, if the level is raised, it will either draw fuel or not. If it does not, we must move on to the next stage.

2. Try Pressing the Bulb

Sometimes all that is required to make things right is to push the primer bulb down till it turns on.

  • You should attempt to press it down while keeping one or more fingers on the portion of the line that connects to the tank itself.
  • After that, release the bulb once more.
  • This usually works, though there is a chance that it won’t be the first time you attempt it.
  • So, before continuing, we advise you to try it out a few times.
  • The bulb should soon start sucking fuel.

If not, the lines might all be backward.

In that case, you’ll have to straighten them out again.

3. The Primer Bulb Might Be Useless

The primer bulb may have developed a fault if nothing has worked this far.

  • It appears that this has been the case for many.
  • Of course, confirming this is the actual cause is always valuable before throwing away perfectly good components.
  • We suggest you try using a different primer bulb even though it is not optimal.

You can identify the bulb as the cause if doing so fixes the issue.

Related article: How to Bypass Primer Bulb on Weedeater – The Ultimate 6 Steps Guide

4. The Fuel Lines Might Need to Be Replaced

Why my primer bulb won’t fill up, you say? You might need to replace your gasoline line with a new one if changing the primer didn’t help to address the problem.

  • The majority advise fixing the fuel line and primer bulb simultaneously.
  • Before new lines are installed, the old ones must be removed.
  • Then, using them as a guide, you must ensure that the new lines are precisely the same size.
  • This task ought to be comparatively simple.

That aside, let’s take a look at other solutions.

5. The Primer Bulb Connected to the Return Fuel Line and Carburetor

The primer bulb is frequently connected to the carburetor via a hose, line, or port in portable tools and other equipment.

  • The fuel line can be connected to an additional port on these primer bulbs.
  • Through this gasoline line, the gas is returned to the tank.
  • However, a faulty or leaky primer bulb is conceivable.
  • To fix this, if necessary, disassemble the instrument to get rid of the primer bulb.
  • Purchase a compatible replacement primer bulb and attach the inlet to the carburetor and the outlet to the fuel line that returns to the tank.

The primer bulb should work after you finish the installation, barring any other problems.

6. There Is a Jam in the Primer Bulb Valve

If your primer bulb is not filling up, there might be a jam in its valve.

  • Every primer bulb includes a one-way valve that lets gas and air in but stops them from coming back out.
  • The base plate of the primer bulb has another hole that allows gasoline and air to enter the area.
  • This fuel and air mixture is pushed into the system when the bulb is compressed.
  • If the one-way valve or the other hole is jammed, the tool won’t be primed by the primer bulb.
  • In that case, examine the valve and the hole for obstructions.
  • Check for any buildup of trash or residue. If the valve is stuck, clean it.
  • A faulty or damaged valve must be changed.
  • If your primer bulb doesn’t include a removable one-way valve, you might need to replace the incorporated part.
  • Look at the additional opening that lets gasoline and air into the primer bulb.
  • To ensure that there is no obstruction, clean this hole.
  • You may utilize compressed air or an appropriately sized poking tool.

Why my primer bulb won’t fill up, you ask? Here’s a Youtube video in that regard:

Why my primer bulb won’t fill up? | How to Fix (Purge Bulb) – YouTube

That’s all!


Briefly put, for leaks and clogs and instances when you wonder why my primer bulb won’t fill up, inspect the carburetor, fuel lines, and primer bulb.

The valves should then be checked to ensure they are in good condition.

In the carburetor’s metering unit, replace any damaged components. It would be wise to get advice from a specialist if you were unsure. That can end up being the best move if you have no idea what you’re doing!

I hope this was of help.