Cold start problem

Hello,

As previously mentioned in this forum I have recently purchased an R107

I have noticed that it has problems starting from cold, almost as if it needs more choke (although it does not have a choke). A search through the google archives suggests either the temperature sensor in the engine block or some kind of cold start valve. Any idea where either of these are located on the M103 engine ? any other possible causes ? the problem is not too bad at the moment as the weather is pretty hot but I could imagine it being awful when it gets properly cold

TIA

Ben