30 years ago when g109A came into Australia nobody liked the bird nest air filters with holes unsealed in back plate. Thus many motor gliders were fitted with LYNX dome foam filters. They certainly stopped injection of dust to engine & have seen this with pawnee 0540 which was disaster on one cylinder (LAME at 100hly did not seat air filter properly.)
Now it appears people have not been checking foam. Note this one from a falke is just rotten ( it came from another club due for formal 2 in march). It just breaks up as you move your finder through it. I do know falke at Darwin on take off missed for a bit then ran again. After inspection there was big hole in foam filter. Next the ex SA cadets falke had no filter at all but there was evidence of foam everywhere in carbie. It seems the limbach just swallow the foam. I am now thinking the foam us not a good idea. If glider were to backfire it could easily start a fire in engine. My friend Geoff Sim from motorcycle shops for 40 years (, owned g109 for 15 years) says consider replacing the foam at 3 to 5 years. Obviously people are leaving it in and not checking annually. Personally in cars I throw away paper filter and fit a K&N filter as gives better air flow (paper as it ages slowly "burns" thus restricts air flow). A friend with a European car changed from paper filter & he could go up a hill near his place in one gear up with the extra power. We in AUS have a much greater need for a good air filter than europe. I do know one Diamona owner fitted K&N filter to his L2000 & works well. Our Sauer S2500 in dimona came with K&N air filter and was told by SAUER to only use K&N as paper gives insufficient air flow which tells a story. If foam filter check it soon is my suggestion. Ian McPhee 0428857642 Box 657 Byron Bay NSW 2481
