Join Date: Mar 2011
Location: 11,500 rpm
Thanked 177 Times in 102 Posts
The lambda bung is on the exhaust manifold, so the O2 sensor will send the info to the ECU which will automatically adjust to keep the compression ratio the same.
This said, the stock ECU is likely to be quite limited in its ability to change it too much.
A few options will be available if the bike is running too lean (not enough fuel for the amount of O2). Have the fuel injection reprogrammed, aftermarket ECU with new fuel maps/powercommander/juicebox.
I personally will probably go for a K&N airfilter, aftermarket pipe, then have the FI reprogrammed to match the stock compression ratio. This service is rummoured to be available sometime soon here in Thailand - selected dealers will be equiped to to put different fuel maps on the CBR for only a few $$.