Current float quality

The floats that Rotax have been using are essentially porous, so they basically contain air, and thus can potentially absorb fuel, although this can be militated against in several ways (some better than others, it seems).  

I am no chemist, so I have a hard time understanding the technology that allows MS to make something from solid epoxy that actually weighs less than gasoline!

Additionally, in the case of a replacement float, they have to make the new float so that it matches both the density and displacement of the float it's replacing, which cannot be easy when using a completely different material.

Hi all:

Seems to be some misunderstanding on what the floats are made of that Bing supplies.  The float material is called NBR rubber.  It is a chemical material that has a bubble inside, it is not porous.  Think of it like a small hard pool noodle.  The material has been used for decades in perhaps millions in carburetors and chemical float applications.  The issue with sinking floats is just bad floats.  With the world switched over to fuel injection on almost everything today it is almost impossible to get good quality control on the process from some suppliers.  For this reason Rotax has been searching to find a reliable supplier that has a good quality.  The latest versions, marked with an "R" on the float, seem to be working well.  The MS floats that I have looked at are somewhat heavy in my view.  (solid material) 

If you search NBR floats on the net you will see them from literally hundreds of suppliers around the world for as many applications as you can imagine.  If your a car guy and you used a Holley carb for example those little floats are NBR material.  Same for almost all of them.  the days of a solder tin float are long gone. 

Cheers

sorry all...bubbles inside, like thousands of them.  If you ever had an aero chocolate bar you get the idea.

Cheers

ps the picture is from a Korean website that makes NBR floats for example.  the micro bubbles are all single, they are not interconnected.