ST183 problems

Help!

Sorry for this being by first post but I'm in a bit of a jam.

We replaced the waterpump on a customers import ST183 (I'm in Australia) and my tech got the intake cam out by one tooth. No problem, I pulled the cover and fixed it. But before putting the cover etc back on I started the motor to make sure it sounded and ran ok, which it did for about ten seconds then stalled.

I have not been able to keep it running longer than about a minute since and it's thrown the ignition code 14.

I've tried a few things and checked absolutely everything in the engine bay from vacc hoses to fuses and found nothing.

I started it cold and held it at 3000rpm and it gave a couple of coughs and seemed alright, so I gradually reduced the revs till I got to idle and it stalled and wont start again.

I've blown back through the fuel line and it seems clear to the tank.

Anyone have any similar experiences or ideas please?