Originally Posted by Geek
If you would like to know how far your particular bike will go with your particular riding style.. fill up both tanks and turn off the petcock to the right tank.
Now go ride it until it runs out of gas. Double that number and you have your fuel range.
Turn the petcock on the right tank back on and continue on your merry way.
Ya that gets you close but there is more fuel in the right tank than in the left on a 990. Ehehe yes I'm being picky