A friend kindly gave me this 310. As it was raining this afternoon I set about it: Most astounding was what came out of the font: see last picture. It would appear to be "crap" in the truest sense of the word, the grains visible are wheat and the smaller one looks like hemp or similar. It also appear to have animal hair in it. Given the small aperture of the filler cap, I am at a loss to understand what did this ?