Today, Bridget and I went with a small group from our church to the Monderosa just north of Nenana. Definitely one of the best hamburgers in this area. This was another test of the homemade air box and the gas mileage definitely improved. From 25 mpg to 28.5 mpg over the same route. Lots of hills and there was a 15 mph north wind. Both trips with the sidecar windshield up. The additional drag is very noticeable as it tends to pull the rig to the right all the time.
The new air box is a bit noisier than the stock set up. All week I have been tweaking the jets and I think that I may be close. I'm trying to figure out if hearing subtle popping through the exhaust while decelerating indicates a rich or a lean mixture. The only problem is that the engine runs hot. I saw cylinder head temperatures of almost 500°F which is way above the Ural recommendation but similar to what I was seeing with the completely stock setup. At least is isn't worse.