Carbureted cb !!!!

[Tev62]

The modern air-cooled CB1100 had to meet international emission standard(s) in order to be marketed viably. That might explain why lump performance is so modest.

I found it interesting to note the CB's compression ratio is 9.5:1 Vs 13.5:1 of the Aprilia Tuareg (660cc twin) I was riding a few weeks back. That is some difference. No doubt emission targets had a great role in that given the tolerances of an air-cooled engine.

Out of interest, some other four pots.:

12.2:1 for the Suzuki GSX-S1000GT
11.6:1 for the Honda CB1000R
11.8:1 for the Kawasaki Z1000SX
14:1 for the Ducati Panigale V4