function excerpt_length( $length ) {
    return 28;
}

function excerpt_more_link( $more ) {
    global $post;
    $link = get_permalink( $post->ID );
    return "<a href=$link class='more-link'>Find out more...</a>";
}

add_filter( 'excerpt_length', 'excerpt_length', 999 );
add_filter( 'excerpt_more', 'excerpt_more_link', 999 );

<article class="<?php echo $classes; ?>">

    <h2>
        <a href="<?php the_permalink(); ?>"><?php the_title(); ?></a>
    </h2>

    <p class="excerpt"><?php echo get_the_excerpt(); ?></p>

</article>