What is a symptom of a defective manual primer on a Johnson outboard?

All outboard gas primers - take it off blow threw gas tank side (from gas tank) and there should be no restriction, you should be able to blow threw with ease completely open all the way threw. Blow through the motor side of the primer bulb and it should be impossible to do so as it has one or two check valves which open when you draw fuel from your fuel tank and close upon releasing bulb keeping the fuel up in to the motor or fuel bowl........