I have just tried to go through the self learn setup for the gas engine management as per a post on here somewhere, but every time I try, it gets to the 30 second mark of the 3000k revs section and coughs just a smidge, or drops about 500 revs (no not a backfire, but like when changing from petrol to gas) and the light goes to blinking every two seconds.
According to the info, this suggests too rich or too lean, and I am to rectify this and try again.

Sooo... the question is.. how do you make the mixture rich or lean on the tickford Vialle?
Thanks in advance