You didn't say if the engine was Electronic Fuel Injected or not. Assuming it is not, and you have to pump the throtle a few times to get it to fire off when it's cold, as normal, Check out the automatic choke. It may be stuck and not functioning properly. Also pump your primer bulb & make sure it will pump up hard and stay that way for a few seconds. If it won't, check out the gas line connections.
