No your not being rude, but until I get even a slight restriction, I will not be changing the filter, at least not on the cleaning intervals suggested. As you mention, the particles that are so small to be seen are also the very ones that are very easy to introduce into a fuel system if you don't take the maximum care in the filter replacement/cleaning in the first place. If your clogging up the filter by introducing matter in the first place, consider a different source for fuel or change your fueling practice. A dirty filter will filter better but restrict more. The visual clues you in about the quality of fuel your introducing. The L 30 series manual suggests you change it every 400 hours, after the intial change at 800 hours not 100 hours. I would prefer not to do the 100 hour cleaning of the filter in kerosene as the manual suggest simply because that crud that the filter traps on the outside could be introduced via the kerosene to the inside and a direct path to the injectors. If your doing the 100 hour cleaning, I would suggest you might be better off replacing it. Crud build up on the filter is not unusual, it does not represent an issue unless it is actually restriciting the fuel supply which is obviously very small. If your changing it at 100 hours and need to, prefilter your fuel. If you just like changing the fuel filter at 100 hours, all the power to you.
