Stuttering / performance issue with certain JS scripts

Working on a very simple pong style game, I have two scripts which cause the game to skip / stutter for the first few seconds of the scenes loading up. If I remove these two scripts, the stuttering goes away. It seems to stabilize after 10-15 seconds and only happens when the level first starts. However, since this game is physics based and the ball is always moving, any skipping, stuttering or slowdown is visible.

I am seeing the stuttering issue on an iPhone 5 but it is not visible on the engine Game window. Using the free version of Unity, I do not have access to the profiler.

Any ideas why these two bits of script are causing stuttering issues?

Thank you

This is a countdown timer. When the timer reaches zero, the game advances to the next level.

 //Countdown Timer (Visible)
             
 var endTime : float;
 var textMesh : TextMesh;
      
 function Start()
 {
     endTime = Time.time + 63;
     textMesh = GameObject.Find ("Text_Timer").GetComponent(TextMesh);
     textMesh.text = "63";
 }    
 
 function Update()
 {
     var timeLeft : int = endTime - Time.time;
     if (timeLeft < 0) timeLeft = 0;
     textMesh.text = timeLeft.ToString();          
 }
    
 //End level and load win screen after X Seconds (Invisible)        
 var timeLimit : float = 63; // 1 minute timer
  
 Invoke("NextMap", timeLimit);    
 function NextMap() 
 {
     Application.LoadLevel("Win");
 }

This is a quit game button which takes the player back to the main menu.

 private var ray : Ray;
 private var rayCastHit : RaycastHit;
  
 //Load Previous button
 function LateUpdate ()
 {
     //Load Previous Level        
         if(Input.GetMouseButtonDown(0))
     {
         ray = Camera.main.ScreenPointToRay (Input.mousePosition);
         
         if (Physics.Raycast (ray, rayCastHit))
         {
             if(rayCastHit.transform.name == "Text QuitToMenu")
             {
                 Application.LoadLevel("L0.0 Menu");
             }                
         }              
     }         
 }