Better for Google to index more or less pages on old site?

I am starting to SEO a pretty old site. There are about 140 pages that Goggle has indexed. The problem is 50% of these pages are really useless. Furthermore many of the pages have duplicate meta and similar content. Should I just work on the top few pages and restrict Google from the rest or should i SEO every single page that i can?

 

use robot.txt, you can create it from Google webmaster tool and upload it in yours site

 

yes I know about robot text...but my question is is it better to SEO top 10 pages and restrict google from the rest....or....try to get to all of the pages?

 

Either option is better than doing nothing. But obviously fixing every page would be best.

Looking for an excuse to be a bit lazy eh?

 

Its not that I am lazy its just that many of the pages are useless in my opinion!

 

You might consider deleting them then? If they have no use.

I don't know if 'useless' pages could hurt your site's chances of good SERP results, but I think the duplicate meta tags and content sure won't help if they match any of the pages you think are still good.