Question about how many results my site returns

I have more than 4,800 pages...

[zeroality]

Hello. I run a site that has a forum with over 98,000 posts however, a "site:url" search on Google only returns 4,800 results.

I even clicked "include omitted (etc)" and it's still only around 4,800.

I used to run phpBB forums but I am on vBulletin now which has the archive feature that's supposedly easier for search engines to index.

I only switched 6 days ago, should I see an explosion on Google as soon as it indexes my site with the new vBulletin?

[zeroality]

Bump.

[Quadrille]

how many threads does the site have?

[zeroality]

Around 6,400.

[Quadrille]

So about three quarters of the threads are indexed; could it be that many of the others were simply one or two posts, and fell foul of the duplicate content issue?

Most forums have a pretty heavy load of code which is pretty much identical from thread to thread; shorter threads might not register.

But do check your navigation - maybe some threads only get a javascript link? Some forums use a 'search' to serve up most pages, and ebd up with complex URLs - that may confuse SEs