The engine cuts out after a few seconds because the jet is blocked in the carb. Remove the fuel tank, by undoing two bolts, one on the front and one on the side, unhook the springs and other connections. Remove the carb carefully, held on by 5 screws, then you will see 2 plastic tubes, one long one short. The shorter one will have a gauze filter on it, remove the filter and blow through the pipe to clear the blockage, clean and replace the filter, re-fit the tank, and start as usual. You may have to start it a couple of times to get fuel into the bowl.
Peter, October 2008