It floats to the top also when you fill the tank.

I would have left it in if I did not find tons of it floating in my fuel filter and having my car run bad.
The last time I filled it up the car coughed and died pulling out of the filling station on the day I was to install my new carb.

This is when I found all the foam fragments in my Fram fuel filter cup.

I left the filters in my carb as well to catch anything that mey get past the main filter.