z421 deck lift spring

[Razorback333]

I saw a picture of another z421 mower, and when lifting the seat on the left hand side, from the rear, there is a piston and a spring. Mine doesn't have a spring. What does it do? Seems to hve something to do with the deck lift.

 

[lugbolt]

some of them had an accessory deck lift assist on them. Maybe that's what you were seeing?