4 Reasons for Primer Bulb Not Getting Hard+ [Affordable Solutions]

Primer Bulb Not Getting Hard

A primer bulb is a very necessary part of running the engine. It is a crucial part of controlling fuel. So, it’s reasonably valuable to keep it good and steady.

If the primer bulb does not get hard, then it can eventually cause a lot of problems. There are several explanations behind the problem.

So, what are the reasons behind the primer bulb not getting hard?

Well, there are many reasons behind this. Like it can cause when there is any shortage of fuel. It can also happen if there is a leak in the fuel pump diaphragm, the float needle is not seated, an air leak in the bulb, a badly squeezed bulb, etc. All of the situations can be solved with proper solutions.

That’s not enough! We have various aspects to share with you. To know all of them, let’s prepare for the article!

Keep reading!

4 Reasons for Primer Bulb Not Getting Hard

Is primer bulb supposed to stay hard? No, a primer bulb is not supposed to be hard always. There is a good significance behind this method.

Let’s first know the importance of a primer and a Primer bulb. 

Well, a primer bulb purifies the gas to improve combustion. It ensures that the gas has gone into the carburetor to create a spark and make the engine run.

Primer bulb – should it stay hard? Why Primer bulb not getting hard or going soft while running?

When the engine starts, it becomes hard for the pressure of fuel and purifies the gas, and sends it to the carburetor. After some time, the fuel pump starts doing the job. The primer bulb can stay hard for up to 4 hours.

And when the engine stops, it becomes soft and stops transferring any fuel. So, currently, we can realize how essential it is to prepare that primer bulb becomes hard.

My primer bulb won’t get hard“- what should be done in this kind of situation? There can be many reasons behind this like mercury 9.9 pro kicker problems.

Well, bother not. Because we have the remedies with accurate explanations for you.

Now you can easily know why the Primer bulb does not get hard. Let’s start!

Primer Bulb Not Getting Hard

Reason 1: Shortage of fuel 

Yes, a shortage of fuel can be a possible reason for the primer bulb not becoming hard. And we have enough reasons behind this too.

A primer bulb becomes hard when it feels the pressure of fuel from the fuel pump. Then it receives fuel and for the daily pressure, it becomes hard.

If the primer bulb doesn’t get enough fuel then it won’t stay hard for a long time. And eventually, it becomes soft and the speed of the vehicle decreases too.

Does your engine stop in the middle of the way? If this happens too, then there is a high possibility that your engine or primer bulb is not receiving an appropriate amount of fuel.

That means there is a shortage of fuel in the vehicle.


First, check the amount of fuel in your vehicle. You can know from the manual how much oil your engine needs. You can then give the proper amount of fuel to the vehicle.

Sometimes if the engine becomes old, it needs more oil to operate. In that case, you will need to fill more fuel in your vehicle.

It can also happen that the fuel you are using in your vehicle is not good or mixed. That’s why you should know which oil is good and which oil is bad.

Here we have suggested some fuels for the boat.

Hope they will be helpful to you.

Reason 2: Leak in the Fuel Pump Diaphragm 

Why does my primer bulb not get hard?  Well, now you have known that a shortage of fuel can be a possible reason for this incident. But what can other things lead to the shortage of fuel besides what we have known?

Well, a shortage of Fuel can also be caused if there is any leak in the fuel pump diaphragm. Because of the leak, the fuel pump can’t carry the proper amount of fuel.

That’s why the primer bulb can’t also get enough fuel from the fuel pump. As a result, because of less pressure, the primer bulb can’t also get hard and stays soft.


The only solution to this problem is to repair the leak in the fuel pump diaphragm. You can take help from an expert for this.

If there are a lot of leaks and the leaks seem to be irreparable, then it would be best to replace the proper leaked part with the new one.

Leaks in the fuel pump diaphragm can be caused by many things. We should take proper care of the fuel pump so that it doesn’t leak.

Otherwise, it can cause a waste of money. And surely it will be a very bad idea to stay in the middle of the river without any fuel in the boat.

Reason 3: Air Leak in the Bulb

Is the Yamaha primer bulb not getting hard? Well, what can be the reasons behind this problem?

Till now, we have got to know about two reasons behind this problem. There can be other reasons too. Like, if there is any air leak in the bulb, then it will not get hard too.

Yes, this is also the reason behind this problem. It can happen if there is any leak in the primer bulb or the valve of the bulb which controls the flow of the fuel.

Because of the air leak, air will enter the primer bulb and create air bubbles and occupy all the spaces in it. As a result, there will be less space for fuel.

Because of the less space, fuel can’t properly be filled in the primer bulb and it can’t create pressure there also. And the air bubble is light too. It cannot generate proper pressure there.

Because of the less pressure, the primer bulb will not get hard too.


Air leaks can cause many problems there. That’s why it will be best for everyone to repair the air leak. 

For doing the work perfectly, you can also take help from a mechanic. He can easily find the location of the air leak.

Reason 4: Worn Out Primer Bulb

Is Mercury primer bulb not getting hard? Mercury is an important reason why a primer bulb expires faster.

Even the ethanol mixed with the new fuel can also expire a primer bulb as well.

Source: Pinterest.com

Besides all of these reasons, if you squeeze a primer bulb a lot, it will lose its efficiency. And besides, after a lot of use, a primer bulb can expire too.

If a primer bulb gets expired it will not be possible to make it hard. It will always be soft and never be hard too.


Now you know all the reasons why a primer bulb expires. What is the solution for it?

The only solution for it is to replace the old primer bulb with a new one. It can cost you up to $16 to $19.

You will have to buy a new one and call a mechanic to replace it.

That’s all. Now you know all the possible reasons and solutions to solve the problems. Hope they will be helpful to you. Well, bass hound 10.2 problems have solutions too. 

Here is a tip for you. You should check the float needle too. If it is not seated, then it can also cause the primer bulb not to become hard.


Can a primer bulb be flat?

Yes, a primer bulb can be flat too. There can be many reasons behind this. Like, such as a blocked air vent, a bad anti-siphon valve, a bad check valve, a vent, blockages, etc. All of these can be the possible cause behind the problem. You should check and solve the issues one by one until you get the solution.

What to do to run a chainsaw if a primer bulb doesn’t work?

Well, some kinds of engines can’t start or work at all without a primer bulb. The engines can’t produce enough energy for running and working through the engine. But there are some vehicles where it’s available that you can start the chainsaw through manual priming. 

Can too much oil harm an engine?

Yes, too much oil can harm an engine. Too much oil can cause the pressure to increase in the crankshaft. Because of this, oil can enter the crankshaft exhaust pipe, and then the combustion chamber. Because of this, the oil will block the suction hose. As a result, the engine will become overloaded.


There you have it. All you need to know about the reasons for the primer bulb not getting hard. Now you also know how to fix those problems and stuff like that. 

We hope you enjoyed this article and can share your queries in the comment section.

Happy fishing! Have a nice day!