Should I get a Warranty -- How many issues have you had?

grandpawmoses

Just general for ECU controlled gas engines. Older carbureted engines were adjusted with modifications to the carb jets.

More worthless info
Most all water cooled engines (cars and bikes) have wide band O2 sensors and they do a decent job of telling the ECU to up the fuel with minor exhaust and intake mods. (A water cooled engine has a narrow band of engine temperature and can use a wide band O2 sensor.) They still need adjustments to their "map" (or tune) for timing, etc. to get the maximum horsepower. ("map" should not be confused with "MAP" or "Manifold Absolute Pressure" which is another factor the dyno tech has to deal with.)
Air cooled motorcycle engines have a very broad band of operating temperature and most use a narrow band O2 sensor. A tune is almost always needed with even small air flow mods. I've closely followed Harley Davidsons' transition to water cooled engines on their touring bikes and believe it was an inevitable move by HD. With stricter EPA restrictions looming, it was the only route.