Hiç blogger kullanmadım. Fakat verdiğin ilk kodu burdan unpack edince kaynak kodlarını açıyor.Daha sonra summaryLength değişkenini 100'den 200'e çıkardım fakat değişiklik olmadıysa bilemiyorum. Çıkan sonuçları da ekledim aşağıya.

var searchFormConfig=
	{
	numPost:9999,summaryPost:true,summaryLength:200,resultTitle:"Result For Keyword",noResult:"No result",resultThumbnail:true,thumbSize:60,fallbackThumb:"http://4.bp.blogspot.com/-b9kfnZlObjc/UGxyCcbigjI/AAAAAAAAFd4/xPPqLCo9uCA/s100/no_image.jpg"
};
function $$$(a)
	{
	return document.getElementById(a)
}
var config=searchFormConfig,input=$$$('feed-q-input'),resultContainer=$$$('search-result-container'),resultLoader=$$$('search-result-loader'),skeleton='';
function showResult(a)
	{
	var b=****.entry?****.entry:"",url,summary,img;
	skeleton='<h4>'+config.resultTitle+' &quot;
	'+input.value+'&quot;
	</h4>';
	skeleton+='<ol>';
	if(b==="")
		{
		skeleton+='<li>'+config.noResult+'</li>'
	}
	for(var i=0;
	i<config.numPost;
	i++)
		{
		if(i==b.length)break;
		var c=new RegExp(input.value,"ig"),entries=b[i],title=entries.title.$t.replace(c,"<mark>"+input.value+"</mark>");
		for(var j=0;
		j<entries.link.length;
		j++)
			{
			if(entries.link[j].rel=='alternate')
				{
				url=entries.link[j].href;
				break
			}
		}
		if(config.summaryPost===true)
			{
			if("content"in entries)
				{
				summary=entries.content.$t
			}
			else if("summary"in entries)
				{
				summary=entries.summary.$t
			}
			else
				{
				summary=''
			}
		}
		if(config.resultThumbnail===true)
			{
			if("media$thumbnail"in entries)
				{
				img=entries.media$thumbnail.url.replace(/\/s[0-9]+\-c/g,"/s"+config.thumbSize+"-c")
			}
			else
				{
				img=config.fallbackThumb
			}
		}
		summary=summary.replace(/<\S[^>]*>/g,"");
		if(summary.length>config.summaryLength)
			{
			summary=summary.substring(0,config.summaryLength)+'...'
		}
		summary=summary.replace(c,"<mark>"+input.value+"</mark>");
		skeleton+='<li><img style="width:'+config.thumbSize+'px;
		height:'+config.thumbSize+'px;
		" src="'+img+'" alt="" /><a href="'+url+'" target="_blank">'+title+'</a>'+summary+'</li>'
	}
	skeleton+='</ol>';
	resultContainer.innerHTML=skeleton;
	resultLoader.style.display="none";
	resultContainer.style.display="block"
}
$(document).ready(function()
	{
	$('body').append('<div style="text-align:center;
	margin:5px 0;
	font-size:11px;
	">Blogger Template By : <a href="http://mkr-site.blogspot.com">MKR</a> | <a href="http://www.ivythemes.com">IVYthemes.com<a></div>')
}
);
function appendScript()
	{
	var s=document.createElement('script');
	s.type="text/javascript";
	s.id="search-feed-script";
	document.getElementsByTagName('head')[0].appendChild(s)
}
appendScript();
function updateScript()
	{
	resultContainer.style.display="none";
	resultLoader.style.display="block";
	var a=$$$('search-feed-script'),newScript=document.createElement('script');
	newScript.id="search-feed-script";
	newScript.type="text/javascript";
	newScript.src="http://"+window.location.hostname+"/feeds/posts/summary?alt=json-in-script&q="+input.value+"&max-results="+config.numPost+"&callback=showResult";
	a.parentNode.removeChild(a);
	document.getElementsByTagName('head')[0].appendChild(newScript);
	return false
}
function resetField()
	{
	resultContainer.innerHTML="";
	if(input.value==="")
		{
		resultContainer.style.display="none";
		resultLoader.style.display="none"
	}
}