Jon Galloway

WordPress feeds offer a choice between Full Text or Summary. The Full Text option is preferable in a lot of cases (e.g. for a podcast), but the feed can grow very large.
One problem with a large feed is that if can exceed the <a href="http://support.google.com/feedburner/bin/answer.py?hl=en&answer=79009" rel="nofollow ugc">Feedburner 512K limit</a>. Your feed may be valid when you first set it up, but eventually when your feed gets big enough, Feedburner will stop updating.
This plugin gives you another setting (available on your Settings / Reading admin page) which sets how many posts should have Full Text. All posts after that will be shown as Summary. This gives you the best of both options – Full Text for new posts, and Summary for older posts. 
<h3>Readme Generator</h3>
This Readme file was generated using <a href='http://sudarmuthu.com/wordpress/wp-readme' rel="nofollow ugc">wp-readme</a>, which generates readme files for WordPress Plugins.

Excerpt Old Posts

This plugin solved my problem with feedbruner.



Greate idea

Shows excerpted content for older posts. This allows more items in the feed while working around the Feedburner 512K feed limit.

followit

s-feeds

Try it out on your free dummy site: Click here => <a href="https://tastewp.com/plugins/feedburner-alternative-and-rss-redirect" rel="nofollow ugc">https://tastewp.com/plugins/feedburner-alternative-and-rss-redirect</a>. 
(this trick works for all plugins in the WP repo – just replace “wordpress” with “tastewp” in the URL)
This plugin allows you to easily switch from Feedburner to the FREE (on the <a href="https://follow.it/features-and-pricing" rel="nofollow ugc">basic plan</a>) and better Feedburner alternative follow.it.
Read more why follow.it is the <a href="https://follow.it/?page=3" rel="nofollow ugc">better Feedburner alternative</a>.
The plugin is very easy to use:
<ul>
<li>Step 1: Download, install & activate it</li>
<li>Step 2: Click on “Apply redirect” for all feeds you want to redirect (most likely your main feed, as well as some comments & author feeds you may have)</li>
<li>Step 3: Connect it to a follow.it account to get access to your subscribers, see statistics etc. (see screenshots)</li>
</ul>
Once the redirect is active, your RSS-url will redirect to your new feed page where users can subscribe to your feed.
If you had former Feedburner subscribers, follow the steps as prompted in the plugin to move them over to your new feed (RSS as well as Email subscribers).
If something is not working in the Feedburner alternative plugin, please post a question in the support forum. Thank you!

RSS Redirect & Feedburner Alternative

Free Feedburner Alternative and RSS Redirect plugin from follow.it.

Excerpt Old Posts vs RSS Redirect & Feedburner Alternative