Strom carb question

[bmounce@impop.bellatlantic.net]

Need some help here:  When rebuilding and reassembling SV Stroms, is
there a 'front' and 'bak' to the piston (I call it a piston, the
assembly with the diaphram on it)?  There are two holes in the piston, I
did not know if there is a certain orientation for these.  Also, the
piston doesn't go up and down very smoothly, is this common?

Thanks for the help, Bill