Give me some advice on New User Engagement

[radare]

If you check out the member list and sort it by "joined date", you'll notice that frequently members sign up and either don't post or post once and never again. I thought that this was because they were joining to download the manual or respond to the classifieds and modified the way that works, prohibiting access until they have a post-count of 5. But this hasn't fixed the problem which indicates I'm totally off-the-wall on what gets people to post.

http://www.xjrider.com/memberlist.php?m ... memberlist

Do you all have any ideas, suggestions or changes that I could make to help get new members to post and engage the community?