07-19-2016, 02:27 AM
(07-04-2016, 09:37 AM)quail_imp Wrote: As you can guess by the thread title I get the feeiling that my bike (2014) is running lean at 2400-2700 RPMs. I say that because my old CB750 had a bad habit of running lean on #4 when pressed hard, and it feels just like that. I think I hear it in the exhaust, but then again I am almost deaf. I think I feel it holding back, but then again I drag my feet when I am tired. It is not something I can put my finger on, it is just a feeling. Anyone else?
Quail,
Of course it's lean under light throttle at low RPM. Motorcycle emission standards make that a necessity these days. Running an engine lean does several things but best performance and throttle response are not among them. Running lean raises exhaust gas temperatures which makes the catalytic converter more effective, raises fuel mileage, and decreases emissions. Bikes are run as lean as possible under light throttle and under heavy throttle they run richer for better response and to keep temps in a safe range. An aftermarket tune runs richer (closer to the sweet spot). Emissions are up a bit although most vehicles will still pass annual emission tests if your state has those, your bike will run a bit cooler, and throttle response from low RPM will be a bit better. FWIW, all cars and bikes are like this whether you can feel it or not.
Chip