Guide on setting - Adjustable Float Height Gauge for LO206, Animal and World Formula Engines

Why Float Height Matters on LO206 Carbs
FMFG Adjustable Float Height Gauge (LO206 Use)

Anyone who has worked on a LO206 long enough eventually learns that the carburetor is one of the biggest performance variables on the engine. People talk about jets, needles, and slide fit, but float height is one of the most overlooked parts of the whole setup. Getting the float height right is not optional on a LO206. It affects how the carb pulls fuel, how the engine responds out of slow corners, and how stable the power is during long green flag runs. The FMFG Adjustable Float Height Gauge makes that job easier and more consistent.

What Float Height Really Controls

The FMFG float height gauge takes the guesswork out of measuring the float level inside the bowl. Most people try to eyeball it or use makeshift methods, but the LO206 carb needs more precision than that. A small change in float height can have a big effect on how the engine pulls fuel under load.

• Float too high can cause:
  • Rich mixture under load
  • Stumble or blubber in the mid range
  • Loading up when coming off tight corners
• Float too low can cause:
  • Leaning out at the end of long straights
  • Loss of top end power
  • Increased risk to engine reliability

The gauge helps you avoid both extremes. The float position controls the static fuel level in the bowl, which then changes how hard the engine has to pull fuel through the emulsion tube. A proper float height balances the mixture, sharpens throttle response, and helps prevent the stutters that many LO206 engines have when the carb is not set up correctly.

How To Measure And Set Float Height On A LO206 Carb

The FMFG Adjustable Float Height Gauge is designed to make float checks repeatable and simple. Below is a basic process that many LO206 racers follow. Always confirm any exact specification with your engine builder or current rule set, then use the gauge to hit that number every time.

1. Shut fuel off and remove the carb
   Disconnnect the fuel line, and drain it to the tank and disconnect from carb. Remove the carb from the engine so you can work on a clean bench. Wipe off any dirt around the bowl area so nothing falls inside. Be very clean and organized! Do not get dirt in or around this area, thats very important... that could cause a jet to clog later, which can ruin a session quick!
2. Remove the float bowl
   Take out the bowl screw and carefully remove the float bowl. Watch for the bowl gasket and keep it clean. This will expose the float, needle, and hinge area.
3. Invert the carb body
   Turn the carb upside down so the float is resting on the needle. You want the float to sit in a natural closed position, not pushed hard into the needle and not hanging loose. Support the carb so it does not rock around while you measure.
4. Place the FMFG gauge on the carb
   Set the FMFG float height gauge on the carb body according to its design. Using a flat edge ruler, or micrometers.. Adjust the gauge to the float height that we include with your carb or engine build sheet. The gauge creates a fixed reference so you can see if the float is too high or too low.
5. Check the contact point
   Look at where the top of the float sits relative to the gauge surface. If the float just touches or lines up with the gauge at the correct setting, your float height is in spec. If the float is noticeably above the gauge, it is too high. If it is below, it is too low.
6. Adjust the float tab
   Remove the float pivot pin and lift the float out enough to access the small metal tab that pushes on the needle. Using a small flat screwdriver or needle nose pliers, gently bend that tab a tiny amount:
   • Bend the tab toward the needle to lower float height.
   • Bend the tab away from the needle to raise float height.
   Work in very small changes, then reinstall the float and pivot pin and recheck with the gauge.
7. Repeat until it matches the gauge
   Keep tweaking the tab and rechecking until the float lines up with the FMFG gauge at the desired height. The goal is a repeatable measurement that you can match on every LO206 carb you prep.
8. Reassemble and double check for leaks
   Once the float height is correct, reinstall the bowl and gasket, mount the carb back on the engine, and reconnect the fuel line. Blow thru the fuel line to fill the fuel bowl up again, be sure you are blowing thru a filter, not directly into the fuel pump... this could contaminate the carb again risking clogging your idle jet.

Doing this process with the FMFG Adjustable Float Height Gauge turns float height from a guess into a controlled setting. You can document the exact setup in your notes and repeat it from engine to engine, or return to the same baseline after a rebuild.

Why This Gauge Helps LO206 Racers

Read some of our guides on the LO206 CARB ---> Lo206 Resource Center / Downloads

The tool sits square on the float bowl surface and gives a solid reference point, so the measurement is always the same from one carb to another. That is a big deal when you are comparing multiple carbs, swapping parts, or chasing a tuning issue that does not show up in jets alone.

With this gauge, you can:

• Check float height in seconds
• Adjust and recheck without guessing
• Match float settings across multiple LO206 carbs
• Keep your tuning notes consistent from race to race

When you are racing or testing, consistency matters. A float that is set correctly helps the engine behave the same every time out. That means your tuning notes are more accurate, your gear and setup tests are more meaningful, and you can trust your data when reviewing rpm, slip, and throttle traces.

Why You Should Not Ignore Float Height

For anyone who wants smoother bottom end, cleaner acceleration, and a stable mixture across the whole run, measuring float height is something you cannot ignore. Many racers blame the carb for problems that start with a simple float level mistake. The FMFG Adjustable Float Height Gauge removes that problem and gives you a reliable way to set it correctly every time.

If you run LO206 at any level, from club races to national events, this gauge is basically required for adding to your toolbox. It is not flashy, but it fixes a real source of inconsistency. Once you use it a few times and see how much float height varies from carb to carb, you will not want to tune without it again.