yamaha outboard fuel pump problems

Facing Yamaha Outboard Fuel Pump Problems?-Here’s How to Fix Them


Want to go on a boat ride but you’re having Yamaha outboard fuel pump problems? This can be aggravating, but it needs to be addressed asap.

Don’t sweat it because we’re here to help you out.

So, why are you having Yamaha outboard fuel pump problems?

Well, our best guess is that your fuel pump has gone bad. Look for symptoms like heating, sputtering or stalling, lack of mileage, and no motorized noise. If you find any of these symptoms then your fuel pump is faulty. Don’t worry you can fix it by repressurizing the fuel system or by replacing it.

We understand that you require additional information. So, just proceed to our next segment for a detailed guideline.

How Do I Know My Fuel Pump Has Gone Bad?

Fuel pumps can go bad at any time, especially if the outboard motor was sitting for a while. Quick identification can ensure quick fixing. So, here are some signs that your fuel pump is malfunctioning-

Excessive Heating

Sudden heating of the gauge could most likely indicate a bad fuel pump. There’s a chance it’s due to something else entirely. But you should still run a checkup just to be safe.


Sputtering is another symptom that you should look out for. This could of course indicate a clogged fuel filter too. Check and resolve any blockages in your fuel system to avoid sputtering.

Rapid Use of Gas

If your fuel is being used up rapidly, your fuel pump has gone bad. We suggest you keep track of your fuel usage. If your fuel tank empties faster than usual, examine the fuel system immediately.

No Motorized Sound

Fuel pumps usually make a noise when engaging. If you can’t hear the motor noise, check your batteries. If the problem still isn’t resolved, your fuel pump is probably causing the issue.

Whether you have a Yamaha, Volvo Penta, or MerCruiser, the symptoms are most likely the same. So, let’s see how we can fix our fuel pump problems.

2 Alternative Ways to Solve Your Fuel Pump Problem-

We have 2 ways you can resolve your problem. The steps are given in optimal order. Follow accordingly for the best result.

Method-1: Repressurize The Fuel System

This method is very short and easy to follow. 

Just pump or squeeze the primer bulb 5-6 times. This will push fuel back into your VST and help you run your motor.

But there’s a catch-

This method is temporary. Your motor will only run as long as the oil in your VST hasn’t run out. Once the oil runs out, your motor will conk out and you’ll have to re-prime again.

Method-2: Replacing Your Fuel Pump

This method is a tad bit time-consuming and long. So we’ve split it into steps to help you comprehend better. Let’s see what the steps are-

Necessary Equipment

First, we’ll need a few useful tools, which are as follows-

  • Safety gloves
  • Pliers, wrenches, and screwdrivers
  • New fuel pump
  • Bolt or screw extractor
  • Fuel
  • Manual vacuum pump
  • New oil filter

Step-1: Remove The Old Fuel Pump And Check The Fuel Pump

This step is quite easy. Remove the bolts or screws using the extractor and your fuel pump should come right off

Then squeeze your primer bulb and the fuel should be directed into the VST. If it comes gushing out the back of the fuel pump then it’s a problem.

Step-2: Disconnect The Fuel Pump From The Hose

Now grab the type of plier you need and twist the fuel pump off the hose. Be careful not to cut or damage the hose as it’s of custom length. But you can buy a new one and replace it so don’t worry.

Step-4: Install New Fuel Pump

Take your new fuel pump and attach the O-ring with it. With the out arrow facing up, put it in the camshaft. Then just screw the bolts back in.

If your camshaft is in the wrong position, the pump won’t sit. Don’t try to push it in. Disable your ignition and turn the key switch to change the camshaft’s position. You can also, turn it with your hand in a clockwise direction. 

Step-5: Test The New Fuel Pump

Connect the new fuel pump to the hoses. Then pump your primer bulb. If the fuel isn’t gushing from the backside, your pump is functioning properly.

Step-6: Replace The Old Oil Filter And Fuel

This step is very important for the longevity of your new pump. Add 2-3 quarts of fuel to your motor. 

Next, do a quick test run for 5-6 minutes to circulate the clean oil. Then extract all the oil out of your motor using a vacuum pump. Change the oil filter and tighten it by hand. Finally, add about 3-4 quarts of fuel and you’ll be all good to go!

Since you need a new oil filter, here are some great choices for you:


These will work just fine for you!

Special Tip

Before you take your boat to open waters, service it a bit. Repair your keels and seal them with Keelshield or KeelGuard. Check your steering cables and run a final test in a test barrel.

That’s all the details that you’ll be needing. We sincerely hope our suggestions were beneficial.


Question: Can I run a boat with a faulty fuel pump?

Answer: No you cannot as it’s not safe. A boat with a faulty fuel pump can no longer supply fuel to the system. It might stop abruptly, leaving you stranded in the middle of nowhere.

Question: Why is my outboard motor sputtering?

Answer: This is most likely being caused by a fouled plug or filter problem. Consider getting a fuel stabilizer if faced with any further problems.

Question: How often should I replace spark plugs?

Answer: We suggest you check your spark plugs annually. It’s recommended to change them within every 100-300 hours.


We hope you won’t face Yamaha outboard fuel pump problems anymore. We’re certain you’ll be able to fix your problem using our guidelines. So, try it out and let us know what happens.

Good luck and see you next time! Happy summer!

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