Setting default values for a different class, similar to vector3

Im trying to create a class similar to Vector3, which allows the default values to be set in the editor.

I set the default values for Vector3 and Vector3i(my class) in a separate class.

 public Vector3 pos=new Vector3(0,5,0);
 public Vector3i centre=new Vector3i(0,5,0);

In the editor it shows the default values for vector3 as x=0,y=5,z=0. But Vector3i(my class) sets the default values at x=0,y=0,z=0.

Vector3i(my class)

 using UnityEngine;
 using System.Collections;
 
 [System.Serializable]
 
 public class Vector3i{
  public int x,y,z;
  
  public Vector3i(int x,int y,int z){
  this.x=x;
  this.y=y;
  this.z=z;
  }
  
  public void convert(Vector3 v){
  x=Mathf.RoundToInt(v.x);
  y=Mathf.RoundToInt(v.y);
  z=Mathf.RoundToInt(v.z);
  }
  
 }