Speaking of "Dirt Dobber" nests, I went through a whole day trying to get a weed eater to start and couldn't. I replaced plug, filter, primer ball, fuel line, new gas. I was getting fire to the plug, but it wouldn't hit a lick. Gave up in disgust and took it to a shop to be fixed. $40. later, found out it wouldn't start cause a d@#$%^ dirt dobber nest had been built in the muffler, and the exhaust was plugged.