Carb floats flaking

At least one of my carb floats was flaking on the inside surface. Also, at least one of my floats have what appears to be gouges on the corners and arc shaped gouges that may be caused by the brass operating lever that closes the fuel inlet valve.

The matronics forum has posts referring to the same flaking and corner gouging problems. There's also a NTSB report of an accident with an aircraft with a Rotax 912 that made a forced landing due to one of the carb's main jet being 30 - 50 percent blocked by foreign material which were consistent with the float material. The float showed signs of flaking on the corner edges.

The floats on mine are the original floats that came with the engine which has approx. 300hrs. I'm ordering 4 new floats. I suggest that all Rotax owners inspect theirs.

Has anyone else experienced this?

I experienced a plugged main jet on one carb shortly after takeoff due to float material flaking. Managed to fly the full patterns and land with no issue, but it sure was an eye opener. Inspect tote floats at least every year, I had some that were less than two years old become fuel logged and starte to deteriorate.

Also be aware that the floats are easily dented and damaged during carb bowl re installation if the bowl is not perfectly square and aligned with the carb body flange. If you don't take great care in reinstalling the float bowls you can actually induce float related failures.

Floats can flake and they can sink. I just replaced a set on an RV 12 that had one float sinking. The symptom is fuel leaking out the vent tube. It can't control the fuel level in the bowl like this.

Floats that flake do need replacement and should be covered under warranty if you are still under warranty. A little mark on the float without flaking is most likely from the MFG process and isn't an issue all by itself. This is usually on top and sometimes on the top corner.