Shifting problem

[carpslayer]

I have a 1969 25 hp evinrude the motor runs great but i am having a hard time with the forward and reverse linkage not shifting from or into any of the settings, I can get it into gear but not back into neutral and vica verca can anyone please help on where i should start looking for the problem.

 

[racerone]

Is there any interference from the " shift interlock "------------This mechanism will not allow it to be shifted out of gear if throttle is advanced too far.