Z500 Fuel Tank Mounting

Just trying to figure out the correct whay that the fuel tank is mounted for my bike.

For a while My tank has been really lose, replaced all the mounting rubers and that was still the case so I thought it was the norm :S

Recently picked up another z500 in parts with a really good condition tank. Tried fitting it to my bike and it was really tight and snug but I couldn't get it to pop though the rear grommet,


I am now questioning if that is what is really meant to happen, I tried forcing it throw :blush: and it broke it.(the rubber grommet)

Can someone please have a look at theirs and see if it just floats their and is held down by he tang that makes contact with the seat. I tried this and it seems to work just want conformation.

Cheers