Reviewing the data collected form the last engine run I could see that 1 and 5 cylinders where not running. Starting with gross mixture variation as the cause I removed the intake manifold and added a modification such that I could try different vanes. Others had indicated that this had helped them get more even mixture. Although I thought the magnitue of my variation was outside the normal I wanted to try this and also check that the manifold was sealed and assembled correctly.
I tried a couple of differnet vanes. 12mm and 20 mm diameter rods and offset to the rich side. No real change in mixture distribution. So it isn' tthe intake manifold geometry.
Vane Bunge Intake Modification
Hole for vanr bunge in flower half of intake manifold
