You see it after a session or first thing in the morning: a small puddle of gasoline under your Briggs & Stratton LO206 carburetor. It’s a common problem, but one that can foul your spark plug, mess up your engine’s performance, and create a safety hazard.
Nine times out of ten, the culprit isn’t a faulty part, but an incorrectly set float height. Let’s get it fixed.
What is Float Height and Why Does it Matter?
Inside your carb bowl, two floats (they look like little pontoons) rise and fall with the fuel level. They’re connected to a needle valve. As the bowl fills, the floats rise and push the needle into its seat, shutting off the fuel supply.
If the float height is too high, the needle doesn’t seal properly, and gasoline continuously overflows into the carb—and out onto your chassis. If it’s too low, the bowl doesn’t get enough fuel, and your engine will starve and bog down on the track.
Getting it right is critical for consistent performance.
The Toolkit
You don’t need much.
- 5mm Allen key
- A dedicated float gauge (recommended) or a digital caliper
- A clean, well-lit workspace
Step-by-Step Fix
1. Remove the Carburetor Bowl:
First, turn off your fuel supply. Using a 5mm Allen key, carefully remove the single bolt at the bottom of the carburetor bowl. A little fuel might spill out, so have a rag ready. Gently lower the bowl and set it aside.
2. Expose the Floats:
You’ll now see the black plastic floats. They’re attached to a pin. Carefully slide the pin out—it should move easily with your fingers or a small punch. Lift the floats and the attached needle valve out as one assembly.
3. Measure the Height:
This is the crucial step. The “height” we’re measuring is actually the distance from the gasket surface of the carb body to the top of the floats when they are hanging down.
- Using a Float Gauge: Most LO206-specific gauges have a go/no-go design. The target is 0.890 inches. The gauge should just slide in and touch the float.
- Using Calipers: Gently hold the carb upside down. Measure the distance from the gasket surface to the highest point on the float.
4. Adjusting the Tab:
If the measurement is off, you need to adjust it. Look at the small metal tab on the float assembly that makes contact with the needle valve.
- If the float is too HIGH (measurement is less than 0.890″): You need to gently bend the tab down, away from the float body. This allows the needle to seat sooner.
- If the float is too LOW (measurement is more than 0.890″): You need to gently bend the tab up, towards the float body. This allows more fuel in before the needle seats.
Make tiny adjustments. A small change in the tab makes a big difference in the height. Re-measure after every adjustment until you hit the 0.890″ target.
5. Reassembly:
Once the height is correct, reassemble everything in the reverse order you took it apart. Ensure the needle is seated correctly and the float pin slides in smoothly. Re-attach the bowl, turn your fuel back on, and check for leaks.
That’s it. You’ve just solved one of the most common LO206 issues and ensured your engine is getting the precise amount of fuel it needs.