A fancy whats it.

[john k]

This is small enough to hold in the palm, its chrome plated, and the name is on the back side, so of course I won't show you that, would give away the ball game.  Been 25 years since it was in common use in shops. 

[J.A.F.E.]

A carb tool I'm pretty sure. Used to set the accelerator pump?

[john k]

It is a carb tool, for the accel pump or maybe setting float level, says CARbureTER on the flip side.