Full Text Feed plugin shows full content....follow the installation steps there,and then goto settings->Reading->For each article in a feed, show=>select Full text and save.it'll work

Full Text Feed plugin shows full content....follow the installation steps there,and then goto settings->Reading->For each article in a feed, show=>select Full text and save.it'll work.if you want to implement via the code means,

<?php if (get_option('rss_use_excerpt')) : ?>
        <description><![CDATA[<?php the_excerpt_rss() ?>]]></description>
<?php else : ?>
        <description><![CDATA[<?php the_excerpt_rss() ?>]]></description>
    <?php if ( strlen( $post->post_content ) > 0 ) : ?>
        <content:encoded><![CDATA[<?php the_content() ?>]]></content:encoded>
    <?php else : ?>
        <content:encoded><![CDATA[<?php the_excerpt_rss() ?>]]></content:encoded>
    <?php endif; ?>
<?php endif; ?>