QuestionI bought a 5.5 hp yard mate roto tiller from a guy who said it worked when he
stored it. I brought it home knowing he had left gas in it for the last four years
without running it. I cleaned the carburetor and got it going but now reverse
doesn't work at all and the tine gear pops out on the least little bump. Just
wondering how the transmission works and how hard it will be to repair?
AnswerBrian,
Roto tillers All have the same basic drives a central archimedes screw or Center gear with 2 side reverse cogged gears chances are the engagement lever and gears have been worn down by the use of the gent who sold it to you depending on how hard the ground was he used it on From the sound of it he used it in a rock laden area.
But the repair would be simple to difficult depending on the drive gears and the central screw.
I would first try adding some 90 Weight gear Oil to it and let it work a bit before opening the lower unit up drain the old fliud out and refill it with 90 Wt Chances are that will solve the problem your encountering The guy prolly ran that oil into thermal viscosity break down which explains the tines popping out of gear If you do need to open it up make a note using a notebook on how the gears are set into the unit this way less guessing later But it is basically like the differential in a car a drive screw with 2 gears both reverse driven from another.
Give the oil change a shot if it helps work it out great If not then try opening the lower end unit and see if any teeth are worn out or broken usually when i drain the unit I take a pencil maget and slip it in to the bottom and check for metal shavings or chunks this tells me how extensive the reapir will be.
Its not a very difficult process If you do have to open the lower end unit up drain the oil from the engine crankcase and the gas from the tank and lay it on one side this way no parts will come crashing out when you pull the side cover off
