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7 Easy Steps to Replace Oil Lines on a Jet Ski [Guide]

7 Easy Steps to Replace Oil Lines on a Jet Ski [Guide]

You can replace the oil lines on a jet ski in seven easy steps, which are as follows:

  1. Read the service manual
  2. Drain the oil
  3. Replace the oil lines
  4. Replace the oil filter
  5. Fill up the oil reservoir
  6. Bleed the system
  7. Test the oil pump
If you want to find out more about the process, you’ve come to the right place.

We at JetDrift have compiled all you need to know into this step-by-step guide.

How to Replace Oil Lines on a Jet Ski

Did you know that broken oil lines are the leading cause of oil injection system failures? To avoid these issues, it’s recommended that you replace the oil lines on your jet ski every 2-3 years.

The entire process takes only about an hour, so doing this replacement as part of yearly maintenance makes the most sense.

Let’s see how it’s done one step at a time!

1. Read the Service Manual

Before you do any maintenance on your ski, it’s highly recommended that you read the service manual.

Oil injection systems may vary depending on the make and model, so you should study and understand it before you start working on it!

If you are not comfortable with this type of maintenance, you should take it to a professional. Doing it wrong can leave your engine without lubrication, which instantly results in an engine seizure.

2. Drain the Oil

As the first step, you have to remove all the oil in the reservoir.

Best practice is to drain the oil reservoir with a suction pump, just stick it in the reservoir and pump as much oil out as you can.

Then remove the return (upper) line at the top only and connect the siphon pump. Through this hose, you can remove the rest of the oil from the reservoir and lines without making a mess.

If you can’t remove all the oil for some reason, just disconnect the hoses and let them fall into the hull. You can then remove the oil from the bilge with rags or a shop vac.

3. Replace Oil Lines

As the next step, remove the oil lines and replace them with new hoses.

The oil supply line is typically a 1/2” or 5/6” rubber hose, while the pump and the intake manifolds are usually connected with smaller, 3/32” hoses. (However, the exact sizes may vary depending on the model.)

Keeping safety in mind, it’s recommended that you replace all oil lines, not just the oil supply line.

Are wondering what kind of hoses to use?

Best practice is to invest in clear Tygon oil lines, which are available at most small engine shops and auto parts shops. They are not only cheaper than OEM oil lines, but they also tend to be more durable.

If Tygon hoses are not available, you can consider other clear tubes rated for engine oil. (However, you should stick to Tygon if possible.)

Attach the oil hoses to the inlets and secure them with Oetiker clamps or zip ties.

Zip ties are much easier to install and do a really good job; this is why manufacturers prefer them over metal clamps. Oil injection is a low-pressure system, so zip ties can easily hold the hoses in place.

Since you will  have to again replace the oil lines on your jet ski in a couple of years, you don’t have to worry about the zip ties aging.

Your other option for securing the hoses to the nipples is to use Oetiker clamps. These metal clamps are durable and virtually last forever, but they are much harder to install.

Also, you have to be careful when you tighten them, so you don’t break off the plastic nipples on the reservoir.

If you are hesitating trying to decide between these options, don’t forget that both manufacturers and most riders use zip ties, so you can’t go wrong with these.

4. Replace the Oil Filter

Contrary to popular belief, 2-stroke jet ski engines have oil filters just like their 4-stroke counterparts.

Besides the hoses, you may want to replace this oil filter in the oil supply line. Make sure to use an OEM oil filter, and don’t make the mistake of interchanging it for a fuel filter.

5. Fill the Oil Reservoir

Fill up the reservoir with oil and check the connections for leaks. You can remove the majority of  bubbles from the system through the oil return line.

Just lower this line in your hand and let some oil drain out along with any bubbles that might be left in the hose. Don’t forget to attach the return line to the top of the oil reservoir.

6. Bleed the System

Bleeding the oil injection means removing the rest of the air bubbles from the system.

How do you bleed the oil injection system on your jet ski?

Simply put, you can find a bleeder screw on the oil pump intended for this purpose. Just loosen this screw and let some oil flow out, which will allow the bubbles to vanish from the system.

After tightening the bleeder screw, you may want to inspect the alignment marks on the pump. (Before doing this step, check that the idle is set correctly.)

7. Test the Pump

As the final step, it’s recommended that you test the system. Although there are many ways to test the oil pump on a jet ski, the simplest method is to hold the pump wide open when you first start it.

(For safety reasons, it’s wise to spray a little oil down the carb before you fire up the engine.)

Locate the lever on the front of the oil pump, pull it wide open, and crank the engine. Let it run for about half a minute at idle while keeping the oil pump wide open.

This trick will prime the 3/32” oil lines and force some extra oil into the carbs.

After 30 seconds, just hit the throttle and the ski should smoke like a factory chimney! The excessive smoke is evidence that the oil has reached the carbs and the pump is working properly.

If you are looking for extra security, you should drain the fuel tank and fill it up with a 40:1 premix before starting the ski.


Replacing the oil lines on a jet ski is not rocket science, and the entire process takes about an hour of work.

As the first step, make sure to read your ski’s service manual tofigure out how its oil injection system works.

Drain the reservoir and remove all of the old oil lines. Install new hoses, and best practice is to use transparent Tygon oil lines and secure them with zip ties.

Fill up the reservoir and drain a little oil from the return hose to ensure the system is filled. Also, don’t forget to bleed the oil pump using the bleeding screw on the side.

Finally, spray oil into the carbs and fire up the engine. Let it run for 30 seconds at idle speed while keeping the oil pump wide open to prime the 3/32” hoses and test the oil pump.

Being cautious, you may want to replace the fuel in your tank for a 40:1 premix before the first start.

Periodically replacing the oil lines is like having extra insurance on your ski, so it’s definitely worth the time and effort!

Disclaimer: This post is for general informational purposes only. Always read your ski’s service manual carefully before you do any maintenance.