Trev, this thing would not have done an hours work, I know the brother in law, you can't use work and Eric in the same sentence, so this tree he cut down was probably a large bush, but in his eyes it would be a tree. I guess I will end up getting stuck pulling the carby to bits, but I don't know what I would be looking for. I bought a real Stihl Farm Boss, from memory it cost about $800 and that was in the early eighties, still a fantastic machine today even though it hasn't done a massive amount of work, but cuts enough wood for the fire each year. Don't think I have ever changed the spark plug