If it's a 2 stroke and it hasn't been used very much the oil in the fuel mixture can 'gum'up the pipes and jets.Strip the carb down and soak in neat petrol or carb cleaner for a few hours.
Or, if it is a cheap chinese thing,as all mine are,find a supplier on t'interweb and order a carburateur (sp)/The last one I bought was £12.00 about 3 years.....problem solved
Ironside are a pretty good make so it shouldn't be difficult getting spares.Oh wait,this is Spain.......