WHAT had been billed as one of the most spectacular motorcycle stunts of all time, a leap over the Great Wall of China, yesterday turned out to be one of the major let-downs. An estimated 60,000 spectators crowded on to the hillsides around the Great Wall at Simatai, northwest of Beijing, to watch British stuntman Eddie Kidd attempt his death-defying feat but came away feeling as though they had missed something. The actual jump, after being delayed for an hour, lasted less than a second and very few spectators were able to get close enough to see if Kidd took his hands off the handlebars. Television pictures on the main evening news bulletin last night showed both Kidd's hands glued to the handlebars. At the scene all most people could see was a black dot rising above the wall and landing on a specially constructed ramp on the other side. The distance between the take-off and landing ramps was about five metres. For some spectators in the valley below, the only indication of what had happened was a police walkie-talkie spluttering ''success, success!'' Following Kidd's safe landing on the southern side of the wall, the crowd seemed to heave a collective shrug of the shoulders and started to make its way down the steep hillside towards waiting buses and cars. The police had reserved the one small car park at Simatai for their own vehicles and had blocked off the main approach road, two kilometres short of the site, so many people were faced with an hour's walk just to get back to their cars. Hundreds of vehicles had been parked in a river bed near Simatai, while many others were abandoned on the roadside several kilometres away from the wall. For many people who had got up at the crack of dawn to drive out to the wall and pay 25 yuan to get in, the show was a great disappointment. Just about the only people who did get a good view of the stunt were the cameramen and photographers who had obtained the ''exclusive'' film rights for the event from Kidd. They were strategically located on the watch tower several metres below the jump site so that Kidd would be seen to be rising over the watch tower behind him, giving the impression of a far more spectacular stunt than actually ocurred. The Beijing Tourism Administration, which organised the event, was probably happy enough however. More than 40,000 tickets were sold bringing in receipts of a cool one million yuan.