pictures of pedal assemblies 340 vs. others

I have a somewhat related question....

I am putting together a 4 speed pedal assembly from a box of parts. How is this sub-assembly supposed to behave when not installed in the car? Specifically, what I'm talking about is the function of the over-center spring. I thought that as I would move the clutch pedal down and up, that the spring would try to bias the pedal into either of these end locations. What I'm finding is that the spring wants to pull the pedal down, and if I pull the pedal up it is extremly unstable like a mouse trap (and a hell of a lot more dangerous!). Also, the spring pulls the pedal down such that it's bending the start depression switch bracket.

Have I done something totally stupid, or overlooked something simple? Any help would be appreciated. Thanks.