abstract controller connected to repository using restrictions - asp.net core 2

Question

My database has several tables to store devices info. All of them with very similar functionality and fields, but they all have a few specific needs.

For this solution I created a data project, where I wrote database access and Models. My interface for table common fields:

public interface IInstrumento
{ /* Common properties here */ }

My models are declared like this:

public class Motor : IInstrumento
{ /* Model specific properties + interface properties here */ }

This models works and can be used to connect with the database using DbContext.

Then I created a business project includin CRUD repositories. I wrote an interface for this:

public interface IInstrumentoRepository<TModel> where TModel : IInstrumento
{
    string Add(TModel obj);
    TModel Get(string id);
    IQueryable<TModel> GetAll();
    int Update(TModel obj);
    int Delete(TModel obj);
}

And specific repositories for each model:

public class MotorRepository : IInstrumentoRepository<Motor>
{
    private MyContext context = new MyContext();
    public string Add(Motor obj) { ... }
    /* etc. */
}

All this stuff worked for me. My problem started when I tried to create an abstract controller for this. Since they all share same functionality, the only thing I have to change are the views and the way I create ViewModels, which is something I can do in every subclass.

My abstract controller looks like this:

public abstract class InstrumentosController<T> : Controller
    where T : class, IInstrumentoRepository<IInstrumento>
{
    protected readonly T repo;

    public InstrumentosController(T repo)
    {
        this.repo = repo;
    }

    /* Methods might be not abstract */
    public abstract IActionResult Index();
    /* ... More methods here */
}

When I try to create the controller...

public class MotoresController : InstrumentosController<MotorRepository>
{
    public MotoresController(MotorRepository repo)
        : base(repo)
    { }

    public override IActionResult Index() { ... }
}

... I get a compile error: The type '...MotorRepository' cannot be used as type parameter 'T' in the generic type or method 'InstrumentosController'. There is no implicit reference conversion from 'MotorRepository' to 'IInstrumentoRepository<....Models.IInstrumento>'.

Of course, the Startup class defines every repository so I can use this controllers.

Any suggestion? Thank you all!