The other issue with my S1 is that when I cold start it it tends to fire up, rev up then die after 3 seconds.

If I continue to do this it eventually starts and runs fine.

I can rev it and hold the revs, but for the first few minutes it runs lumpy.

I'm thinking auto-choke.

Anybody point me in the direction of the auto-choke so I can swap it out for a new one? Or could you think of something else it might be.

After a couple of minutes the car runs perfectly - hot starts perfectly too....