How Do I Get My Friend To Stop Texting Me All The Time? Without Being Rude?

I have a really close guy friend who likes me more then a friend, but i don't like hime the same way. I don't mind texting sometimes, but when he texts me twice a day, everyday, it can get quite annoying. Now, don't get me wrong,he's great, but seriously?! I just get so tired of always texting him, especially when the conversation is going virtually nowhere. Any suggestions on how to nicely tell him that I don't always have the time or want to text him all of the time?? I've already used the "gotta go (put excuse here) ttyl" too many times so something other then that...would be good.

Thanks