I've heard of guys using a filter between the muffler and the vent tube to filter out some of that crap. I've never done it, seems extreme. But I do like to have a filter between the tank and the carb. Some guys don't even like that. I had an issue where my fueling pump broke down and I started using my old Control line syringe to fill my tank. But the syringe was so old that the rubber piston had deteriorated and black rubber particles went into my tank and eventually clogged my filter. Two deadsticks later and I knew something was wrong. So any crap or crud can do you in.