Regardless of the confusing part of your post, here is my piece of advice:

>How do I tell them I'm just tired? or can I call it burn out?

Why not tell them the truth? Explaining to them just how you did here with us in your post.

Seems to me that "I feel tired" may indeed not be the best excuse to call in sick for work... however, **the fact that your motorcycle is broken and needs fixing *is* a valid excuse for being late or not being able to go to work one day.** So, I suggest you go with that (or, if this is in retrospective, that was what you should have done).

An honest, yet valid and effective message to send could be (or could have been):

>Hello [HR or person you are writing to].
>
>Sorry for writing at this late hours, but after leaving work today my motorcycle broke half way on my way home. After several hours I managed to get home, but I need to take my bike to the mechanic to give it a proper fix.
>
>Thus, I won't be able to arrive at work, but I will surely be able to be there tomorrow after it's fixed.
>
>Thanks, threeFatCat