thanks guys, i was planning to fit an orignal solex if i couldn't sort the strommy. I will take a photo of the adjustable jet and post for info/interest/reference. It is my belief that the power valve is at fault, i just couldn't believe the car ran so well(comparatively) like that.

Also rare spares didn't stock jets for strommys anymore (Hobart anyway) and it wasn't worth the bother of hunting around too long for. I could also solder the original jet if i was keen as well...but i'm not.

now that i know that the engine will faulter/hunt/stop with the valve wound down, i can investigate further.......that means i will probably end up with the solex.

Thanks for the advice, i shall return.