LO206 carb tuning is very important if you are into competitive go-kart racing. There are quite a few tuning that you can do to the carburetor of a LO206 engine.

So, how to conduct LO206 carb tuning?

You can do LO206 carb tuning by adjusting the float height and the float drop. You can also adjust the idle speed screw and the idle mixture screw for further tuning. To optimize your carburetor, listen to the noise of your engine and the performance on the track.

Are you still confused about how to perform LO206 carb tuning? Do not worry. Read this article to learn all about it.

How to Perform LO206 Carb Tuning?

To perform LO206 carb tuning, follow this procedure:

Things Needed

Get these things first before you start to tune the carburetor of your LO206 engine:

  1. A wrench kit
  2. A Phillips screwdriver set
  3. A small flathead screwdriver
  4. A drip pan
  5. A towel.

Then follow these steps for LO206 carb tuning:

Step 1: Remove The Carburetor

Firstly, locate the carburetor connected to your LO206 engine. The LO206 engine uses a Walbro PZ-22 carburetor for mixing fuel with air. You will find the carburetor attached to the intake manifold of your LO206 engine. Then follow this process to remove the carburetor:

  1. Rotate the slide lock on top of the carburetor in the counterclockwise direction until it becomes free. 
  1. Pull the slide out of the carburetor.
  1. Disconnect the fuel line from the carburetor using an appropriately sized wrench
  1. Hold the carburetor and use a wrench to unscrew the two bolts connecting the carburetor to the intake manifold.
  1. Remove the carburetor and then put it in a drip pan upside down to drain the remaining fuel.  

Although cleaning the carb does not follow under tuning, you can still do it if you want.

Step 2: Disassemble the Carburetor

To disassemble the carburetor, follow this process:

  1. Once the fuel has been drained, place the carburetor on a towel.
  1. While keeping the carburetor upside down, using a screwdriver, remove the two screws on the edge of the carburetor. These screws hold the float bowl to the carburetor.
  1. Remove the float bowl from the carburetor. If the carburetor was not drained entirely, expect the remaining fuel to gush out now. Your carburetor float is now exposed along with the main jet and the smaller pilot jet.
  1. Remove the bowl gasket and keep it with the float bowl.

Pro tip: check the bowl gasket for signs of wear to prevent oil leaks in the future. Always have a few spare bowl gaskets when disassembling the carburetor in case of emergencies.

  1. Remove the float pin from the carburetor float by simply pulling it out of the two slots.

Pro tip: it is very easy to lose the float pin if you are holding the carburetor at an angle. So make sure that you are careful with the float pin.

  1. Remove the float with its needle from the carburetor. 

The carburetor of a LO206 engine is very easy to disassemble. You may also choose to upgrade the carburetor altogether, especially if you have a Predator 42 engine. Getting a carburetor upgrade for a Predator 420 can be easier than you think!

Step 3: Adjust the Float Height

You need to adjust the float height to affect the engine performance at higher RPMs. To adjust the float height, simply follow this process:

  1. Hold the float upside down in your hand.
  2. Locate the rectangular tab in the middle of the float height. 
  3. Insert your flathead screwdriver into the opening of the tab.
  4. Gently bend the tab down to increase the float height. On the other hand, if you need to decrease the float height, bend the tab up. 

If the float height increases you will get less fuel into the bowl. Likewise, a lower float height will give you more fuel in the bowl. A small change in the bend will create a big change in the float height.

  1. Put the float back in its place and reattach it with the float pin.
  2. Turn the carburetor upside down so that the float of the carburetor hangs down.
  3. Measure the height of either end of the float from the top to the edge of the carburetor. The recommended float height of this carburetor is Float 0.860 inches to 0.880 inches.
  4. If the height of both ends of the hanging float is not equal, remove the float pin. Then take out the carburetor float and twist one of the ends of the carburetor a tiny bit. Do this until the height on either side of the float becomes equal.

Your float height adjustment is now complete.

Step 4: Adjust The Float Drop

To adjust engine performance at the lower end of the RPM range, follow this process:

  1. Pull the retaining clip out of the slide. The clip will be located on the opposite side of the narrow end of the needle of the slide.
  2. Remove the needle from the slide.
  3. Locate the 5 slots on the broader end of the needle.
  4. Move the needle clip up or down to adjust the air/fuel mixture in the carburetor. Lowering the needle clip will make the mixture richer. On the other hand, moving the needle clip up will make the mixture leaner. The needle clip lies in the 3rd slot by default.
  5. Put the needle back into the slide and reattach it with the retaining clip.

Your float drop has now been adjusted successfully.

Step 5: Adjust The Idle Speed Screw

To adjust the RPM of your LO206 engine when idling, follow these steps:

  1. Reassemble the carburetor by reattaching the fuel bowl.
  2. Put the slider back into the carburetor.
  3. Close the slide lock on top by rotating the slide cover in the clockwise direction.
  4. Reattach the carburetor to the intake manifold of the LO206 engine and reconnect the fuel lines.
  5. Once the carburetor has been fully assembled and reconnected, locate the idle speed screw close to the slide cover. 
  6. Take your go-kart to a racing track, like a K1 speed. If you live in Atlanta, however, there are many good outdoor go-kart tracks in Atlanta you can try.
  7. Turn on the LO206 engine and let it idle. Listen to the sound the engine makes as it idles.
  8. Insert a flathead screwdriver into the slot of the idle screw.
  9. Rotate the idle screw in the clockwise direction to increase the idle speed of the engine. On the other hand, if you want to reduce the idle speed, rotate the screw in the counterclockwise direction.
  10. Adjust the screw until you get the right tune. A lower idle speed will make the engine vibrate and can even cause engine stalling. A higher idle speed, however, can reduce engine performance. You will want the idle speed to be at or just under 2,000 RPM for a good performance at the lower end.

Your idle speed screw has now been adjusted successfully. Be careful while being on the track like at  a k1 speed.

Step 6: Adjust The Idle Mixture Screw

To adjust the fuel mixture composition when idling, follow this process:

  1. Locate the idle mixture screw of the carburetor. It can be found close to the air intake line. The idle mixture screw in this carburetor is an air bleed. So, unlike most carburetors, this screw adjusts the air supply and not the fuel intake.
  2. To increase the richness of the mixture, rotate the idle mixture screw clockwise. This will limit the air entering the carburetor. Likewise, to get a leaner mixture, rotate this screw in the anticlockwise direction. This will increase the air going into the carburetor.
  3. Adjust the screw until you get the highest RPM when idling.

Your idle mixture screw has now been adjusted successfully. 

Frequently Asked Questions (FAQs):

Which is better fuel injection or carburetor?

A fuel injection system is better than a carburetor. This is because fuel injectors can increase the efficiency of your engine. They can also increase the performance of your car and improve throttle response. However, a carburetor is much cheaper than a fuel injector and is easier to maintain. So, lower-end engines usually contain carburetors, while higher-end ones contain fuel injectors.

Why carburetors are not used anymore?

Carburetors are not used anymore because they are difficult to control and are less fuel efficient than fuel injectors. Moreover, carburetors give you less power and performance in comparison to modern fuel injectors. But carburetors are still used in some lower-end engines due to their affordability, simplicity, and ease of maintenance.

What are the 7 circuits of a carburetor?

The 7 circuits of a carburetor are float, choke, idle, main metering, power enrichment, accelerator pump, and secondary barrels. All these circuits of a carburetor must work together for the carburetor to function properly.


So, now you know all there is to know about LO206 carb tuning. Tuning the carburetor of your engine can give you a very big advantage on the tracks. But it is important to be careful while tuning to avoid damaging the carburetor. I hope this article helped you easily tune your carburetor to your liking.

That is all for today. Thank you for reading my article. Goodbye and Goodluck with your upcoming races.

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