Engine cutting out

[chrisis]

Hi all, please bear with me as this is my first posting.

I have fully rebuilt my 05 636r following a smash (requiring a new frame)
My problem is this - i turn on the ignition and the varios pump priming and butterfly moving noises are heard. Press the starter and the engine starts straight away - runs for a max of 5 seconds and stops (this is the same whether on tickover or on part throttle) if i press the starter again the engine will not start. if i turn the ignition off and on again the noises are heard again and the engine will start and run for another 5 seconds.

any help will be appreciated

thanks

Chris