Polaris Sportsman 500 Carburetor Leaking – 5 Causes & Fixes

You suddenly notice the carburetor of your beloved Polaris Sportsman 500 is leaking. There can be multiple reasons for this to happen.

So, why is your Polaris Sportsman 500 carburetor leaking?

Polaris Sportsman 500 carburetors can leak due to incorrect float height, worn or stuck needle and seat, junk inside the carburetor, etc. It can also leak if the carburetor screw is overtightened or corroded. However, taking apart and cleaning/rebuilding the device should fix it.

We have gathered all the possible reasons behind the issue and possible solutions for your convenience. 

How to Fix Polaris Sportsman 500 Carburetor Leaking?

A leaking carburetor is very common, and the solutions are simple and easy. Here is a basic summary of the reason behind this issue and possible fixes.

ReasonSymptoms/Indications Solution
Incorrect float height Slow throttle response slow, muffled engine note Adjust the float height
Worn or stuck needle and seatEngine will stall or hesitateRebuild the carburetor with a new needle and seat
Contaminated oilWeird rumbling noisesReplace oil and the filter
Debris inside the carburetorEngine cranks, but won’t startTake the carburetor apart and clean up its insides
The screw for the drain was over-tightened or corrodedDrain plug will fall out or get damaged.Replace or retighten the screw properly

Reason 1: Incorrect Float Height

The float height determines the fuel flow in the carburetor. Excess fuel is drawn onto the carburetor when the float level is high and overflows.

You can check the float height by measuring the fuel height. Here are the steps-

  • Hook up a clean tube at the drain hole of the float bowl.
  • Take out the drain screw allowing the fuel to come into the tube.
  • The fuel will either be above or below the seam of the float bowl.

Usually, the fuel level should be right below the seam level. Your vehicle’s user manual should have exact instructions for this. 


When the float height is incorrect, the engine will make muffled noises, and you’ll experience a slow throttle response.


If the float level is incorrect, you must fix the float height. Here is the Polaris Sportsman 500 carburetor adjustment process-

Tools Needed: Slide or digital calipers.

  • The first thing you need to do is take the carb apart so the float can be accessed.
  • It’s essential to drain it first, so make sure you do that. 
  • Ensure the float bowl has been removed. You will need a set of Vernier calipers or digital calipers for more precise measurements.
  • An excellent method to measure the floats is to tilt the top of the carb at about 10 or 2 o’clock until the floats fall back far enough to close the float valve without squeezing the spring. 
  • To determine the float height, you must measure it without compressing it further from the bottom of the carb’s exposed lip to the top of the float. 
  • You can adjust the height by bending the tang up for a higher float or down for a lower one.
  • When the float height is low, the vehicle runs rich; when it is high, it runs lean.

Here is a video for a better understanding-

Reason 2: Worn Or Stuck Needle And Seat

The needle and the seat will prevent any fuel from entering the carburetor at a certain level. So, if they are worn out or stuck, you’ll have fuel leaking out of your carburetor. Also, your engine will be flooded so that it will be stalled or hesitate.

Here is how you can check whether they are worn out or stuck. Take apart your carburetor and detach the needle and the seat. The seat has a conical shape, and the needle is pointy. If they seem deformed, that means they have worn out.

Also, the needle should fit into the seat and come out easily. If it does not, that means the needle is stuck.


Engine will stall or hesitate due to fuel flooding the carburetor. 


If the needle and the seat are worn out or stuck, it’s better to rebuild the carburetor. Below we have briefly told you how to rebuild Polaris Sportsman 500 carburetor– 

Tools Needed: Carburetor kit

  • Take out your carburetor and separate all the parts.
  • Clean all the parts using a full-immersion carburetor cleaner. Make sure the cleaner is not too alkaline or acidic.
  • Rinse all the parts and leave all of them out to dry. 
  • Spray the gaskets and sealing rings with penetrating oil.
  • After all the cleaning and polishing, start reassembling all the parts. Start with the air horn, then the gasket, needle, and seat. 
  • Adjust the float level and drop according to your owner’s manual.
  • Reinstall all external linkages and mat the air horn to the main body. Install and adjust the linkages properly.

Rebuilding carburetors is not that complicated but time-consuming. So, before rebuilding one, have more than an hour at hand.

Reason 3: Contaminated Oil

If the fuel is contaminated with gas or anything similar, it can cause the carburetor to leak. To check, smell the oil inside the carburetor. If it smells like gas, it might have been contaminated. 


Check for loud, weird engine noises when starting; engines tend to do that with contaminated fuel.


When your fuel is contaminated, there are no options except changing the oil and filter. This could be a lengthy process, so give your mechanic a visit. Or, if you insist on doing it yourself, here is a guide-

Tools Needed: Ratchet, 6mm Allen socket, 8mm socket, torque wrench, 2.5-inch oil-filter wrench, gloves, eye protection.

Draining the oil:

  1. Ensure that the transmission is in park.
  2. Start and idle the engine for 2-3 minutes, then stop it. This will warm the engine up.
  3. Remove the oil dipstick access panel. This should be on the right side of your vehicle.
  4. Clean the area around the dipstick before removing it. Keep it away for now.
  5. Place a drain pan with a rag under the crankcase. This will help prevent the splashing of oil.
  6. Clean the area around the drain plug before completely removing and draining the oil.

Replacing the oil filter:

  1. The oil filter is in the right wheel well; use a wrench to turn it counterclockwise and remove it.
  2. Clean the surface area of the crankcase where the filter was connected.
  3. With fresh engine oil, lubricate the new oil filter’s O-ring.
  4. Install the new filter by turning it clockwise. 

Replacing the drain plug:

  1. Clean the drain plug with a clean cloth thoroughly. Make sure there are no scratches.
  2. Put a new ceiling washer on the plug too.
  3. Replace the drain plug.

Refilling the oil:

  1. Refill the engine oil through the dipstick port. Be careful not to overfill it.
  2. Reinstall the dipstick and clean up any residual fuel from the vehicle.

Now that you are all done, start your engine and allow the engine to idle for 2-3 minutes. Then stop it and check for any leaks. 

Reason 4: Debris Inside the Carburetor

2003 Polaris 500 ATV Dirty Carburetor

If you have read this far, you have probably taken apart your carburetor. If so, then look for any junk or debris inside your carburetor. Examine your needle and seat in particular.

Having your carburetor and its parts clogged with dirt is one of the reasons why your carburetor might leak. So, while you’re at it, give it a thorough check.


With a dirty carburetor, your engine will crank but won’t start. 


If you find your carburetor full of dirt, you will have to clean it. But the carburetor cleaning process is a bit different. Here is the whole process to make your life easier.

Reason 5: The Screw For The Drain Was Over Tightened or Corroded

If your carburetor still hasn’t returned to its regular state, you should check the drain screw.

The drain screw works as a gateway for the fuel. Through this pathway, the fuel comes out; loosening or tightening the screw can impact the pathway of the fuel flow. 

Overtightening the screw will disrupt the regular flow, causing the carburetor to leak. If left like that, the drain may fall out or get damaged. This could also happen if the screw is corroded. 


If the screw is damaged or corroded, get a new one to replace it. Usually, the screw is located on the bottom of the carburetor bowl. Remove it with a screwdriver and replace it.

But if you suspect the screw is overtightened, loosen it a little bit.


Why is my Polaris sputtering?

Carburetor problems, like tuning issues, vacuum leaks, or gas leaks, are the most common causes of your Polaris sputtering. An ignition issue can also cause sputtering problems in some cases. 

Is the Polaris Sportsman 500 a good quad?

Yes, the Polaris Sportsman 500 is a good quad. When it was released for the first time, it was considered the best quad choice. It has a perfect blend of features and design. Even by today’s standards, it could still be an excellent choice.

Why does my carburetor bog down when I accelerate?

Your carburetor is “bogging” because too little fuel is being delivered to your engine. In many cases, the accelerator pump system is to blame for similar reactions in the carburetor. 

What causes a carbureted engine to stumble?

A carbureted engine will stumble when too much of the transition slot is uncovered at idle. You can eliminate the hesitation by increasing the throttle opening to increase the RPM.


It’s normal to be panicked when you see your Polaris Sportsman 500 carburetor leaking. But you don’t need to, as the issue is not fatal and is easily repairable. However, some solution processes can be lengthy, so getting expert help is better if that seems like a hassle. 


Leave a Reply

Your email address will not be published. Required fields are marked *