Now I've been really bad recently for constantly bemoaning the poor running of the car and I haven't really driven it much because its never running right.
Well this afternoon after the F1 was finished I decided to stop being mr grumpy and Naomi and I went to Welwyn to see some friends who helped us build the car. It was about 1hr 10mim away and gave a very good opportunity for some good lomg steady state cruise data gathering.
Drilling out the idle jets has made no noticeable difference, its still terribly lean below 2000rpm. Interestingly cruising at 2400rpm (70 in 5th) the AFR dropped to about 12.5:1. It would appear that all my rod and jet changes for cruise mixture have been pointless because all the time I was evaluating the changes I was never truly on the cruise circuit, I was still in the troublesome lean idle/transition circuit!
I think I've just about had enough with this carb. It simply will not meter the fuel correctly at light throttle. Even with my fairly hot cam it should be better than this, anything below 2000rpm and its bucking and surging at 15:1 or worse AFR regardless of what we do to the mixture screws or idle revs. Time to procure a smaller carb!
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