Is an object with an update function possible? (C#)

If I have a class, and In another script, I create an instance of that class, is the update function usable?

Nothing I put in it seems to run.

The class:

 using UnityEngine;
 using System.Collections;
 
 public class MM_Timer {
 
     float delayy;
     float time;
     public bool tik = false;
     bool randmode;
     float min;
     float max;
     bool paused = false;    
 
     void Update () {
         if (time < delayy && tik == false && paused == false)
         {
             time += Time.deltaTime;
         }
         else if (!paused)
         {
             tik = true;
             if(randmode){
                 delayy = Random.Range(min, max);
             }
         }
     }
     public bool tick(){
         if (tik){
             tik = false;
             return true;
         }
         else{return false;}
     }
 
     public void start(){paused = false;}
     public void puase(){paused = true;}
 
 
     public MM_Timer(float delay, bool autostart){
         delayy = delay;
         if (!autostart) paused = true;
     }
     public MM_Timer(float minDelay, float maxDelay, bool autostart){
         min = minDelay;
         max = maxDelay;
         if (!autostart) paused = true;
     }
 }
 

Just in case, my Script:

 using UnityEngine;
 using System.Collections;
 
 public class bow : MonoBehaviour {
 
     public GameObject arrow;
     public Transform shotpos;
     bool canfire = true;
     public static float firerate = 0.5f;
     MM_Timer timer = new MM_Timer (firerate, true);
     
     void Update () {
         if(Input.GetButton("Fire1")){
             if(canfire){
             Instantiate(arrow, shotpos.position, transform.rotation);
                 canfire = false;
             }
 
         }
         if(timer.tick()){
             canfire = true;
         }
     }
 }