I ended up putting this engine together. I pulled down the carb, cleaned and reassembled with new gaskets. Sourced a new starter gear. Pulled down the starter as is was seized and got it sorted. Installed the second hand tank and brackets. Installed the second hand muffler. New fuel hose and filter plus a head gasket and it was finished.
Threw it on the Tractor 11 and took it for a run. Changed the oil again just to be sure and then put around 12 hours on it slashing 6 foot lantana, ferns, gum saplings and anything else in its way. What a great old machine. The engine has run perfectly with no smoke or strange sounds. Very happy.
