This site is an affiliate for companies including Amazon Associates and earns a commission on qualifying purchases.

How To Fix a 2-Stroke Oil Pump System


How to fix a two-stroke oil pump system.

Two-stroke oil pump systems are popular among motorcycles, bikes, and other vehicles such as snowmobiles or boats. They were made popular because they allow the mixing process of oil and fuel to become automatic and not require premixing. So, how do you fix one if it is not working?

Fixing a 2-stroke oil pump system is a simple and straightforward process. Here’s a simple rundown of the steps:

  • Check the fuel tank
  • Smell the gas
  • Check and clean fuel and oil tank vents
  • Unblock carburetor lines
  • Inspect fuel filter

Now that you have an idea of how to fix your oil pump system, it is time to learn a little bit more about what these systems are and how they work. Read on to learn a bit more about these handy pieces of equipment.

Fixing a 2-Stroke Oil Pump System

The steps above should give you a good idea of what you’re getting into when you commit to fixing a 2-stroke oil pump system. Here are the details for fixing the oil pump system. 

Step 1

Check the fuel tank. If there is no fuel, check the fuel indicator to see that it moves/registers freely.

Step 2

Smell the gas. Caution: Gasoline fumes are poisonous, explosive, and carcinogenic. If the odor smells off, the gas should be replaced. Old gas can damage all parts of the engine or clog the gas line.

Step 3

Make sure that the fuel and oil tank vents are clean and that the fuel, oil, and carburetor lines are clear and unblocked

Step 4

Check the fuel filter to see if it is clogged or dirty. If it is clogged, it will stop gas from flowing to the carburetor.

Step 5

If you are still not certain that the fuel is reaching the carburetor, remove the engine spark plug, disconnect the carburetor line, and hold it over a container, crank the engine a few times. If the fuel does not sputter into the container, the carburetor may still be blocked. If this is the case, take it to your dealer or mechanic (source).

What Is A 2-Stroke Oil Pump System?

Motorcycles and other similar engines require that there is some sort of lubrication introduced directly to the cylinder and crankcase to keep them lubricated and for cooling (source). Prior to the invention of the two-stroke pump system, the typical method was to utilize premix. 

Premix is a method of mixing a little bit of oil with the fuel. The ratios needed to achieve the proper level of premix vary based on the engines that they are being concocted for. 

This process with the four-stroke systems is much more hands-on and requires more manual labor than the two-stroke systems. 

Overall, premix is practical for any engines that will be stationary or used in short spurts or distances. This allows you plenty of time to get the correct ratio of premix. 

However, for any street bikes or boats that get a lot of usages, it is not practical to have to constantly be checking the premix and making sure that the mixture is correct.

This is where the two-stroke system comes into play. This system is designed to be fully automatic by mixing the gasoline and oil to keep the cylinders, pistons, and other engine parts correctly lubricated for operation. Especially helpful to any riders who go on long-distance jaunts, this only requires that the rider or driver keeps the gas tank and the oil tank full.

Newer bikers or boat owners would especially prefer this type of system, as there is less upkeep required and one less thing to worry about while they are learning the ins and outs of their new bike. They will be able to fill up their gas tank and get their oil changed, and they will be all set and ready to go.

What are the Advantages of a Two-Stroke Oil Pump System?

As stated above, the biggest advantage of the two-stroke oil pump system is the ability to not rely on premix (source). If your system requires premix, then you would need to travel with both a gas can and premix oil. When filling up, you would have to mix these to the correct ratio before filling up the bike.

One key issue with mixing is the need to ensure the right ratio, which can be extremely difficult if you already have gas in the tank. The entire ratio can be thrown off if there are additional gas and premix that will be included with what you are putting into your tank. 

Essentially, this would require that you get your gas tank to empty every time before filling up. This is impractical for any road bikes.

When using a two-stroke oil pump system, you do not have to worry about premixing at all, as the system will take care of it for you. This is a big-time advantage when it comes to convenience and ease of use. However, there are certainly some disadvantages associated with the two-stroke system. 

What are the Disadvantages of a Two-Stroke Oil Pump System?

Despite them being more intuitive overall, these systems do require significant upkeep in other areas. After the fuel tank is empty, the system needs to be primed. First-time bike owners may not know that this is required and, while it does not immediately cause engine failure, it typically results in the engine not receiving the correct amount when it comes to oil flow.

Over time, this can result in some damage being done to the engine and the bike and can harm the bike’s overall functionality. If this were to eventually cause long-term damage to the engine, the cost of repair or replacement of the engine would be extremely costly.

In addition to this, these bikes also require winterization when they have oil injection systems. While this process can be done by professionals, it often comes at a price. It is important to be sure that this is done properly. However, otherwise, there can be detrimental effects on the bike.

While the winterization may be expensive, if it is not done correctly, there can be plugs that form in the lines due to old oil. This can cause other parts of the engine to gum up and sometimes result in oil starvation or even a blown engine.

As you can see, the disadvantages of this system can sometimes result in extremely costly repairs or even ruin a bike or other vehicle. Total engine failure is a nightmare to take care of and can lead to more issues down the road, depending on how the repairs are handled. There are definite benefits associated with these systems, but the disadvantages are hard to ignore.

So, are Two-Stroke Oil Pump Systems Worth It?

This one depends on the type of vehicle and engine that they will be used in as well as the type of rider or user of the vehicle that you are. If you are a newer owner of a bike and are just looking for something to go on road trips with or cruise the highway, it may be worth getting the two-stroke system for convenience and ease of use.

However, if you are a more serious and handy biker or someone who rides dirt bikes or in competition, you may prefer the traditional premix system. It boils down to how much knowledge you have about how the engines work and how willing you are to put in the work and maintenance needed to maintain the bikes’ pristine condition.

Either way that you elect to go, it will require upkeep to maintain your bike’s pristine condition when you are riding. Like any other vehicle, there will always be general maintenance that will be necessary to keep riding. The key is understanding the type of maintenance and upkeep you would feel comfortable handling yourself and how confident you are in your abilities.

Teddy Henderson

Teddy is always fiddling with small engines, picking up thrown-out string trimmers or tearing apart dirt bikes. He shares what he learns along the way. Hopefully, you'll have less headaches than he has had by learning from his mistakes.

Recent Posts