Andrew Ng, Tokyo
Try taping him again, only this time record your own sentences and time them. Play them as a model and give him the timings. Tell him to match them as closely as possible. This should be a clear illustration for your student. Then it's all down to lots of practice to retain natural intonation. For anyone without a tape recorder, just model the sentences and use your watch.
Good luck.

Nidhi Chaudhary, India
I am a language trainer, and have to work with people who have a high rate of speech. I use I use ‘syllable time reading’, this is when the student has to read each syllable and not words together, and it’s close to chanting. The student does not read for meaning of the text hence no emotions are required; it’s flat without punctuating the speech. Ideal number of words read are 75 in 60 seconds. This works, if done on a regular basis.

 
Priyadarshini
Get the student to read piece from a novel/ an article at the required pace and time him while he does so.

Coral, China
My chinese teacher asked us to perform a stage drama in which the sentences should be slowly said so as to express the emotion clearly. I wonder if it can also be effective in English studying. You can try. I wish you success!

Biola Ufeli. Nigeria
I'm a speech trainer. Recently I had a student who is a radio presenter and her speech was really fast. She was taken off air and what I did was to teach her 'stress in the English Language' and that helped. She slowed down.

Renee Lajcak, USA
I've had a few students who are under the mistaken impression that if they speak as fast as a native speaker, they will be more understandable. Of course, faster speech is necessary for natural intonation and linking, but it can be overdone. First, I would make sure that the student understands that faster is not always better. Then, I might have students give short presentations to each other or in groups, asking them to give hand signals to the speaker, such as a hand outstretched with palm down to signal "Slow down" and a hand rotating in a circle for "Please repeat or rephrase." When this students sees lots of other students telling him to slow down and reminding him to do it, he may not only get the idea, but start to learn when to monitor himself.

Ben BT, Japan
I have a similar high-school student whose English is good but he gets excited and speaks too quickly and really minces his intonation so that no-one has any idea what he's on about. I don't really know how to deal with it but I tend to interrupt him and repeat his point in a way that the other students can understand (speaking slowly and clearly), in the hope that he will realize the pointlessness of rattling off his sentences if the teacher has to 'translate' everything he says for the other students.

Dialla Crush, Angola
One of the best way to help encourage him to slow down his/her speech will be to quietly remind him the importance of making himself clearly understood as some of the other students might not have the same accuracy or fluency.

Teresa, England
Try asking him to make sure he pronounces the little words that are often swallowed in a schwa.
Select texts that might be read aloud over a microphone, for a biggish audience; the microphone or accoustics in a large hall often "swallow" part of the information words and so they are not enough on their own (even when spoken clearly) for the listener to grasp the whole message. The audience needs to hear these small words to aid their catching the information words accurately.
It is very difficult to speak quickly while trying to pronounce these little words! and, what is more, you will be focusing on an important skill in public speaking and acting.

H. E. S., England
1. Allow him to read suitable English material FOR DICTATION to the rest of the class.
2. He must observe the usual practices for Dictation Speed
(a) Normal-speed reading;
(b) Piecemeal reading, each segment twice;
(c)Re-reading as (a).
3. Let the Class give their opinions.
4. Repeat all with a different passage of English text.