I sifted the compost yesterday and, since there were no stones, I thought I would run the lumps (sticks, grass roots, pits, etc) that didn’t sift through the chipper / shredder (CS). However it has been raining a lot lately and there was enough sticky clay to gum up the works. Once I stopped the engine I couldn’t restart it. At least I have taken the guard off the CS before so it didn’t take me long to clean out the gunk. And, yes the lumps are smaller now and mixed up with weed and twig bits ready for some more composting action.