I have a Honda lawnmower which is self propelled. It was expensive to buy but its been a great mower The self propelled bit has stopped working. I am looking for a reliable repairer in south Dublin that repairs Hondas. (The place where I bought it won’t return my calls).
It might be something very simple like a a loose wire.
Before you haul a heavy mower across town it's worth spending 30 minutes on youtube to see if you can fix it yourself (if you haven't already of course)