Motivation often will depend on your mindset, how your mind is operating and how your body is feeling.
If we can be motivated to do something really special, then we have the skills to be motivated. When we need to do something we are not so keen on, feeling unmotivated often draws the "thing" we need to get done into a big long event when it needn't be.
If we have a task to do and we dont really want to do it, often we will fall into a negative mindset and start dragging our feet and think of every excuse not to do it.
One tip I have is to make that thing the first thing you do. Get that "thing" out the way first, and then you have the rest of your time doing stuff you do enjoy.
Remember we have the skills to be motivated for the things we find pleasure in, so therefore the skill set sits within us to do the strategy that gets us to our goals, we just chose another neural path if we arent keen on doing a task, we feed the lack of motivation mentally and physically.