Me seat just won't stay on.... it keeps coming out of it's front mounts.... it looks like when I install it, and lock it in it slides back. Is this common or ?
As the seats age they loose the original shape from heat and compression. The pieces under the seat that engage are wider than original and with force from sitting they pop out. Try a wood clamp to pinch it closer together I have used heat but I think the foam ended up getting hard.
Be sure that it hooks into the middle tabs. I had the same problem (it cost me a race win). I ended up squeezing the seat to make it more narrow and quickly install it before the seat spread back into shape. Now that it is engaged on all the tabs, it's rock solid. I wanted to avoid a heat gun.
Like Double said, you have to be absolutely sure you've got the hooks/tabs in the middle engaged as your sliding the seat forward into position, before locking it down.
Speaking from experience as well...
I had issues with mine not staying engaged in the front also. I used some washers and shimmed the front mount on the tank (moving it back just a bit)...solved my issue.