My advice (for the negative cents it's worth) is to train yourself slowly. And don't try to get rid of the burst writing completely. If you're in the zone, go for it.
And when you're not, focus on writing a little bit each day. Maybe use a writing prompt and aim for 200-300 words, without even trying to put story to them. Get your mind in the habit of writing, without it feeling like it's being forced to write (if your mind is anything like mine, it reacts very negatively to the idea of being forced to do anything).
But don't burst the burst, man.
of course, we're all different writing beasts, so the above may or may not be useful
ETA: oh, and good stuff Aggy and soapy (and anybody else i've missed)!