What are some good ways to keep inspired for when you're writing a book to a deadline?

I'm trying to finish a historical fiction children's book in time to get in in to a competition I really want to enter by the end of July this year and I can't keep myself motivated to get it written. I know what I'm puting in it and everything, it's just that Solitare always seems more interesting. I know, really know, my characters and I'm identifying well with them - sometimes a bit too well. I just can't keep writing on paper and get it out of my mind. Any suggestions...and no puns on the Solitare please.