i have a sailfish with twin 200 2001 mercurys saltwaters carb engines. engines start fine the first time but after they run they don't want to start. there are two ways i get them to fire. 1st is a fast start throttles engaged then i pump them with long turn of key. or i just do a long turn of the key almost like they are flooded and need to burn off fuel. i know it contradicts it self but either way will get them going. any ideas?