OK you say it has never run for a few seconds which requires a question and that is: is that needle limiting device functional and is it preventing the needle from closing completely then allowing at least four full turns open.

I think if you get rid of that limiter (an abomination) completely screw the needle closed then back out 3 and a half full turns (360 degrees), you will find success and hopefully a nice maiden flight.

By the way I googled Forde, What a lovely town.

John