Please forgive my ignorance before i start,I'm a complete beginner in this Hobby,and this is my first post.I have purchased two fibre glass trawlers each measuring 30"x10"and both have electric motors ,one brushed and one unbrushed.Because I have no history of the boats,never having met the previous owner,I have no idea of model or motor size etc.Can anyone tell me if there is a formula for calculating engine size based on model size?.Would it be a better option to start from scratch and install my own motors and again if so what size.I've attached a couple of pics of the motors,hopefully someone may be able to give me some idea.Thanks. Jim