Hello
I recently fitted a dellorto FZD carburettor to my 1970 Giannini look-alike 500L. The engine is 650cc and when I took it for a 20 mile test drive it was amazing. It was scarily fast, I reached an indicated 100 kph and that makes me think that suspension and steering will have to be next. However, as I got nearly back home the engine started to hesitate a little and on inspection of the spark plugs it would appear that the mixture is far too rich. I took the main jet out and checked the size, it is 135 and I have ordered an assortment of smaller jets to see if I can get the balance right.
But this leaves a couple of questions which I hope someone can help with. Firstly, when I fit a smaller jet, do I need to adjust the fuel air mix on the carburettor or is changing the jet sufficient? Secondly, when I removed the main jet fuel came out of the carburettor, on refitting the old jet the car now won't start. Could there be an air-lock, is there any technique for restarting an FZD fitted engine after removal of the main jet?
Thanks for reading this far, I hope someone can help.
Mauro
I recently fitted a dellorto FZD carburettor to my 1970 Giannini look-alike 500L. The engine is 650cc and when I took it for a 20 mile test drive it was amazing. It was scarily fast, I reached an indicated 100 kph and that makes me think that suspension and steering will have to be next. However, as I got nearly back home the engine started to hesitate a little and on inspection of the spark plugs it would appear that the mixture is far too rich. I took the main jet out and checked the size, it is 135 and I have ordered an assortment of smaller jets to see if I can get the balance right.
But this leaves a couple of questions which I hope someone can help with. Firstly, when I fit a smaller jet, do I need to adjust the fuel air mix on the carburettor or is changing the jet sufficient? Secondly, when I removed the main jet fuel came out of the carburettor, on refitting the old jet the car now won't start. Could there be an air-lock, is there any technique for restarting an FZD fitted engine after removal of the main jet?
Thanks for reading this far, I hope someone can help.
Mauro