[Neilnaz]

Thanks for all your responses. I do not have detail of the exact engine modifications but recall reading a receipt from the engine work where the Porsche dealer stated that they had trouble setting the timing to the S specs. I will have to hunt down the actual words. The trail of paperwork I have is difficult for me to interpret (for instance part numbers of cylinders used during the engine rebuild). I will post it on this thread so that someone can shed some light.

As far as I understand (I have no evidence to the contrary) the Webers are original to the engine and the engine is definitely original (in terms of the core) to the car. I do not have any evidence of modification to the distributor or the heads but nothing that disproves it either.

If I did know what had been done to the engine then I presume people would point to a spec of timing, choke sizes, venturis (etc) that would work. As I do not, as it stands, have much or any of this then there is little merit in pointing me towards a likely set up that would work.

Maybe a different approach would be:
1) check and adjust the float levels
2) confirm what the carb specs are currently
3) clean the carbs
4) establish whether the problem persists
5) post my findings

Incidentally, how easy is it to confirm the carb specs and identify components? I will do a search to see how it is done - I am used to SU carbs!!!

Cheers and thanks for your input,

Neil