PeeJay is correct. You need to stop changing the image sizes in articles and change your own preferences if you do not like the default size. By forcing image sizes, you are forcing every reader of the article to view the images at the size you want them to, which is not necessarily the size they want to view the images at. The whole point of not forcing image sizes is to allow users to have some flexibility in how they view images and you're selfishly taking that away from them.