How long will i be able to edit my post, so i can let people i have updates?

I went to edit an old post and it did not let me edit it/

This is the thread
http://www.rcuniverse.com/forum/m_5755872/tm.htm

I know u go to the first post and change it there but how much longer will i have before it Locke's me out??? or if i do it on a regular basis it will continue until i stop posting for a while?

I will not have any update anytime soon so i was just wondering?

Oh and will the spel check ever be put back on? I got the goolgle toolbar to fix the speeling errors i was just wondering?