DexterDay from another thread, "I have personally had a MS 360 with an intellicarb that would bog under load. Had an OEM filter and several seen it run at the GTG at Swags in May. Revved like a mad man. But once in wood? It lost all power. Took me a month of testing to figure it out. I put almost $600 in that saw and racked my head over what was wrong Had new Everything.. Except the air filter. The filter had been blown out, but after years of fines, it was just "plugged" up." Anyone else ever run into this problem? My saws are old and were bought used, I've never replaced the air filters. I blow the filters out with compressed air, they clean up fine and look good but now I'm wondering if I'm missing out on some power that I didn't know about. The saws seem to run fine....
That's exactly the way that 360 was. They look great, but over time, some of those fines are so small, that they plug up the flock filters. I wish I would have taken a video of that saw running with the old filter. It ran decent without a load. But as soon as it went under load, it lost almost all power and fell on its face.
Plus a lot of those "fines" have a coating of either bar oil or oil from the exhaust on them. That causes them to gather more and more fines over time.