MouseY movement

Hi I would like to move my ship towards the Y axis of the mouse, i’ve checked the game input to mouseY

So far I have the code pasted below. Also a screenshot to elaborate this issue
I have an object with no rotation but the camera is rotated -90 to show a side view.
I have no gravity selected.

The top and bottom of the ship are in the scene editor 1.4 and -1.4 ( aka the min & max a ship could move thus its boundaries )

However the ship never reaches my max or min point as you can see in the screenshot. Its like it has a sort of delay or offset.

I am new to unity, i have many years of AS3 knowledge but awkwardly new to unity, but loving it! and so far I can’t seem to bend my head around it.
Thank you!

using UnityEngine;
using System.Collections;

[System.Serializable]
public class Boundary
{
	public float xMin, xMax, zMin, zMax, yMin, yMax;
}

public class PlayerController : MonoBehaviour
{
	public float speed;
	public float tilt;
	public Boundary boundary;
	
	void FixedUpdate ()
	{
		float moveHorizontal = Input.GetAxis ("MouseY");
		//float moveVertical = Input.GetAxis ("Vertical");
		Vector3 movement = new Vector3 (0.0f, moveHorizontal);
		rigidbody.velocity = movement * speed;
		
		rigidbody.position = new Vector3 
			(
				0.0f, 
				Mathf.Clamp (rigidbody.position.y, boundary.yMin, boundary.yMax), 
				0.0f
				);

		rigidbody.rotation = Quaternion.Euler (0.0f,0.0f, rigidbody.velocity.y * -tilt );
	}
}

I’ve plugged in your code into unity and it seems that the code is working perfectly. I even played around with the settings and the cube never went past the min and max limit. Other than the cube jitterbugging a bit the code just seems fine in my perspective. Are you sure you didn’t accidentally pressed “14” instead of “1.4” for min and max setting, that’s the only possible fix I can up with. Or am I misinterpreting your problem entirely?