remove the spark plug and tip a small cap full of petrol into the chamber. screw the plug back in. induce petrol into the float chamber....there's usually something around or under the carb such as a rubber bubble or a spring loaded plunger to press a few times. pull starter several times (may take a while). hopefully your engine will now start. think this works by sucking more fuel through after the initial startup.
Neil Burton, July 2004