Somethings been living in my fuel tank

[pipemakermike]

After some unexplained engine speed changes yesterday I decided to have really good clean through.  I had already cleaned the tank (or so I thought) before fitting it to the model by half filling with alcohol shaking it and emptying through a filter paper and found nothing of note after several cleanings.  I checked the filter in the model and it was clean.  However, today after my day out flying yesterday I opened the filter and found a significant number of "things"  2 small insects, 1 ball of solder and a number of unidentified bits.  None of these had made it through the filter but after the cleaning I had done I didn't expect anything!! Looking at the actual filter there are some black tiny things too small to work out what they are but they are on the tank side of the filter.
Today I have filled it with methanol plugged it and run a few cycles in my ultrasonic cleaner.  I have ultrasonically cleaned the filter assembly and I await the results next time out
Some pictures from my PC microscope(the filter is 1/4" diameter):-

[Jim Kraft]

Is that not what they all say, Get the bugs out and all will be fine. Debugging is more art than science. Looks like you did a fine job.

[Steve Helmick]

If you're using an open Uniflow inlet, put a filter on it to keep the gnats and seeds out. The Master Airscrew fuel filters (small and plastic) are close to being ideal for this task.  Plug it onto your uniflow inlet with a short bit of fuel hose.  Cut off the forward spigot if you want.  Steve

[Jim Carter]

   I always wanted to know what made a Fox 35 burp .... now I see!!      

[Motorman]

Bugs eat castor oil.

[Fredvon4]

years ago I removed the inlet screen(s) on the back plates of many Cox .049s with no problem and a slight increase of rpm

Moved to Texas and started having constant problems with the 1/2a engines....discovered that Bermuda grass seed is small enough to cause much grief and even cleaned out many Fleas .....

Back to screens and panty hose on every opening... problem solved