I still run 2 engines.
A Mugen MR B01 .28, just pulled because it's leaking fuel from the head.
And a Werks B7 .28 which I just finished rebuilding and I am going to put back
into the Mugen. (Need to be broken in).
Funny enough, fuel mileage for me isn't too bad. I don't tend to have a
really heavy finger and I tend to roll on the throttle so my fuel consumption
is about 8 or 9 minutes per fueling. (At last when I ran the Ninja)