I've just bought my first petrol lawnmower. It's a Gardenmaster SP21, powered by a Honda 5.5 4-stroke engine. It was secondhand, but had never been used. I find it very, very hard to start. My son eventually managed to start it and used it for only about one minute, then stopped it so I could have a go. Very hard to start again. I only went about 10 yards before stalling it. Now it refuses to start. What are we doing wrong? I presume we should have the choke on to start, then move the lever to the fast position in use? Thanks for any tips-I know very little about engines.