Turn the machine up-side-down and remove the gearbox cover, 4 torx screws. Remove the cutter, 2 further Torx screws, I found a screw that secures the bottom cover to the engine had come adrift stopping the large gear (about 4 inches in diameter) from turning. Refit the screw using a spring washer or shakeproof washer, why not treat the other screw the same? Slop plenty of grease into the gearbox and re-assemble.
Philip Burbidge, June 2005
