Jet sizes, Fractional mm or arbitrary sized?

Jet sizes, Fractional mm or arbitrary sized?

I was just reading the wiki and it seems that a #56 bing jet is not the same bore as a #56 Dell'. It also appears neither are sized at the fractional mm (eg. #56 = .56mm).

Re: Jet sizes, Fractional mm or arbitrary sized?

For some brands that does apply but others it does not.

maybe this will help.

http://www.mopedarmy.com/wiki/Image:Drill_sizes_per_jet.jpg

Re: Jet sizes, Fractional mm or arbitrary sized?

On the wiki for Keihin carbs it states that the jet size is the total cc that will pass through the jet in 1 minute. That explains why they are not directly related to the drill size.

Re: Jet sizes, Fractional mm or arbitrary sized?

Ok, that explains it, thanks. Actually the cc/min would be a more useful measure anyway I bet, if one were really splitting hairs, or they wanted to run an equation of comparative flow volumes. Well, I'll just shut up and go with the chart for drilling :-)

Re: Jet sizes, Fractional mm or arbitrary sized?

I'll bet with a tach (to get rpm), stroke length, bore size, and a little bit of math, you could actually calculate what jet you should be using for optimum fuel consumption and max power.

though i don't do any of said math without said money