I originally thought about a narrow band sensor but was told that they aren't great for tuning as they only tell you that you are lean or rich but don't tell you by how much. I know that the stoichiometric air/fuel mixture is 14.7 which should be achievable with a fuel injection set-up. I'm guessing carbs will give quite a variance with different rpms, loads, temperatures, etc. so I'll have to play it safe so it never leans out especially at WOT. If it stops raining and they sweep the sand off the roads I'll make some more progress on this.