Zenith Stromberg Float question

Hi, I am rebuilding my ZS 175 and the piston float would not return to the bottom. I removed the long tension spring under the top cap that covers the diaphragm and stretched it out. Now the float piston seems to return by itself after pressed up by hand nice and smooth. Just wanted to know if I'm on the right track-or not. I have another spare ZS carb. and the piston float returns very fast.....appreciate any feedback! Thanks.

Check the piston for any carbon build up preventing smooth motion up and down, also make sure the needle is engaging the main jet correctly (make sure the needle is not bent). If that spring needed to be stretched you might swap it with the one in the other carb... maybe the spring is worn out?

Without the screw top damper in the carb it should drop like a rock. If not, the sleeve is gummed up.