Hi SC - we have 'met' before, on a garden and lawn query!
What behaviour problems are occurring at school? It IS difficult to motivate reluctant readers, particularly if there are behaviour or 'learning' issues that make it harder than normal for them. And I once worked in a Reception class where the children knew all the books off by heart, and often didn't have it open a the correct page.
I'll give you a couple of ideas that may help, but mainly just keep reading WITH and TO him as much as possible, and 'keep cool', so reading hopefully become more of a pleasure, and less of a chore:
ONE - An inexpensive and easy to use book, that can encourage children with reading, spelling and writing, and really help them to understand Phonics, is reviewed in the MN Book Reviews section. Just search ‘Phonics’ and my name.
TWO - When reading harder books with a child, get him to point to words as he goes along. If he knows the word, or can sound it out, he can say it. If he doesn't know the word, he can hover his finger over it, and YOU say the word for him. Don't stop to analyse or discuss the word at this stage, but try and keep the 'flow' of reading going. Review difficulties at the end, if you wish to. This way, he has the satisfaction of reading more difficult books, without the fear of getting 'stuck' on words.
Good luck, and let me know if I can help further.
[Tried to 'post' this yesterday, but MN site was sluggish!]