Joel Cool - followed your instructions and spark plugs were a breeze but I had a real hard time getting the exhaust bearings reinstalled, especially in the dark on the side of the highway - seems to have helped though. Too bad I started with a full tank, and another 25 gallons in the aux tank - anyway, ran it all dry - took me all night - walked a couple of miles to a truck stop - wish I had thought to put some in a can from the aux before I used it all - next time I'll know.
Overhead jumped 3.5mpg as soon as I started back to the house - I'll keep you posted on the progress.
Thanks for the suggestion!!

 

I quit after trying to remove the spark plugs! They must be hidden well, I couldn't find them. So I went back to my way of calculating. My overhead is pretty accurate compared to the calculator. Overhead 16.4, calculator 16.5 (filled to rim all 3 times and calculated). I was impressed. One thing for sure, when you idle these beasts for 10 minutes or more, it's amazing how the calculations turn out.