Understanding Squeeze Bulb Priming on Detroit Diesel Powered Boats

October 5, 2020
Understanding Squeeze Bulb Priming on Detroit Diesel Powered Boats

Squeeze bulbs are essential to feeding fuel to your engine. Many savvy boaters take the time to understand these components to ensure their engine operates at peak efficiency. Though some people can sometimes overlook the importance of squeeze bulbs, they’re crucial to the engine’s performance.

As you begin understanding boat primer bulbs more thoroughly, you’ll want to learn the basics of how squeeze bulbs work and how you can prime them to get the best performance. You’ll also want to know more about some common troubleshooting steps you can take in case your squeeze bulb doesn’t work correctly. This article will provide you with that information.


The Basics of Squeeze Bulb Priming for Marine Engines

A squeeze bulb is a piece of equipment installed on the fuel hoses of the outboard motor. These bulbs prime empty fuel lines so fuel can be brought through the outboard engine’s pumping system and into the engine. Squeeze bulbs are especially crucial since the integral fuel pumping system needs liquid to function.

When installed, squeeze bulbs have to be placed at an appropriate height and distance from the fuel tank’s level. If they’re not set at an optimal location, they won’t be effective. The need to put them at the right height and distance comes from the limited nature of the bulbs’ elasticity and displacement.

Due to the bulbs’ limits, their ability to handle vapor or air is limited as well. If there are any leaks, no matter how small, the fuel lines and bulbs can become useless. Anyone who uses a squeeze bulb should ensure there are no leaks to keep the system running correctly.


Effective Squeeze Bulb Priming Tips

If you want to prime your squeeze bulb for optimal operation, you can take a few actions to ensure there’s no excess air in the boat primer bulb and the rest of the system. Lifting key components and loosening parts are simple actions that can ensure your squeeze bulb runs at peak efficiency.

Check out some top squeeze bulb priming tips below:

1. Lift Pump and Squeeze Bulb

Sometimes you may notice the fuel isn’t flowing through the fuel injection pump. Before you loosen anything, you can lift the squeeze bulb and engine pump together. By raising both simultaneously, you can often get the fuel to start flowing through the injection pump again.

2. Loosen the Second Filter and Listen for a Squeak

If fuel isn’t flowing into the first filter, slightly loosen the second filter and start pumping. Wait for the first filter to fill and the second one to start spilling liquid before retightening. Try both the lift pump and the squeeze separately and together, listening for a squeak.

When you hear a squeak coming from the injection pump return check valve, you’ll know you have optimal fuel in your fuel rail. If you don’t hear a squeak, you still have air in the system, and you should keep pumping until it’s gone. Since squeeze bulbs are highly susceptible to air, any squeeze bulb priming technique should make sure there isn’t any air inside them.

3. Loosen Components Placed Beyond Off-Engine Filters

To let the air out, you can also loosen parts installed beyond the off-engine filters. This loosening is an effective method of bleeding air, as the squeeze bulb is much better at pumping air faster than the engine hand primer. Try different parts, loosening them as needed, to get your engine working most efficiently.


Troubleshooting Squeeze Bulb Tips

While squeeze bulbs are reliable, issues can sometimes arise in them. Before you immediately replace your whole system, you can do some troubleshooting to find the source of the problem. Sometimes, there are some easy fixes, which can save you money and help you get more life out of your squeeze bulb.

Below, you can find the primary causes of trouble in squeeze bulbs and ways to fix them.

Fuel Line Troubleshooting

When you run into issues with your fuel line, you must understand that fuel only flows one way. Fuel goes from the tank to the engine. When your fuel line and outboard are working correctly, the fuel pump for the engine generates a small vacuum in the fuel. The tank’s atmospheric pressure then forces the fuel into the engine. When the system runs optimally, your check valves will be partially open, while allowing the fuel to flow at the rate the engine needs.

At the end of a boating session, boaters often disconnect the tank’s hose, allowing the engine to run until all its remaining fuel is used up. If you’re having trouble starting up your boat again and there are issues with the fuel line, you’ve likely not primed the engine and hose.

Priming the squeeze bulb is crucial because your fuel pump can’t work correctly if it attempts to pull anything but incompressible liquid. To get the fuel line ready to function again, squeeze the fuel primer bulb until the fuel hose is filled with liquid fuel.

Suction Issues

Empty squeeze bulbs utilize their check valves and their own flexibility to pump air until they bring fuel into the hose and bulb. To pull the incompressible liquid fuel through the hoses, the bulb relies on suction to get the liquid flowing properly when the hose is empty.

Leaks in the suction side of the bulb can harm the suction ability and make it so the squeeze bulb can’t pull liquid into the hoses. If you notice fuel isn’t filling the hoses and flowing into the engine, you should check for tiny leaks in the suction area of the bulb. This section is located between the bulb and gas tank.

Other Common Squeeze Bulb Issues

Alongside checking fuel lines and leaks that could be causing suction problems, you can troubleshoot other issues fairly quickly. To start, you can inspect the bulb for cracks, loss of elasticity or aging. If you don’t find any issues in the bulb, move to the hose connections for any leaks.

For systems with crimp type clamps, you can replace them with screw-turn hose clamps. Examine the hoses for softening or cracking. If these fixes don’t work, you can switch your squeeze bulbs for new ones, which should be simple to add to your fuel system. Also, replace your hose assembly and squeeze bulbs every two years.


Purchase Marine Engine Replacement Parts From Diesel Pro Power

Purchase Marine Engine Replacement Parts From Diesel Pro Power

Besides monitoring your squeeze bulb’s conditions, you can keep your engine working optimally by investing in high-quality replacement parts from a trusted supplier. Diesel Pro Power will help you find the exact components you need for your marine engine. With over 24,000 happy customers, we’re prepared to provide you with top-quality customer service and parts.

Browse our selection of marine engine replacement parts today. If you have any questions, contact us to speak with our friendly customer service team.

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