A fair bit. You have to disconnect the racks as the governor is mounted on the blower, plus the fuel lines since the fuel pump is mounted there too. It also has a shatload of oil that pools in it that doesn't drain out when you shut down, which means it will make a hell of a mess. There's an inside snap-ring that retains the driveshaft for the blower you have to remove from the rear to extract the blower driveshaft - and you CANNOT drop that inside the gear train or you're in BIG trouble. Stuff a shop rag in there good so if you DO drop it it doesn't go down inside the engine! You know Murphy, right? [links]