I guess that explains a few things but doesn't change the fact that the larger pistons create more torque and Hp. I've had no problem with mid grade gas. Makes sense if the compression isn't much different.
When I did a compression check on my 904, both cylinders hit right at 175. That doesn't seem much more than the stock would be. BUT, the bike runs great and has all the power and more than I'd hoped for.
