View Single Post
Old 12-10-2012, 06:06 AM   #15
roger 04 rt
Beastly Adventurer
roger 04 rt's Avatar
Joined: Nov 2011
Location: Massachusetts
Oddometer: 2,296
Originally Posted by rforrester View Post
I like the sound of this! I have a 2005 1200GS as well as a 2007 Ducati S4RS Monster. The two cylinder Ducati was TERRIBLE below 5000 RPM and it was due to the fact that the bike was on a closed loop ECU system below 5K (or 4K, not sure where its is set). In a closed loop, correct me if I am wrong, the engine Fuel/Air mixture is dependent on the data from the O2 sensor. There is really no "data" sent from the sensor. All the O2 sensor does is send a different level of voltage to the ECU and the ECU adjusts the fuel/air mixture depending on the voltage the O2 sensor sends. I bought a very simple solution from the folks at for my Ducati. $80

The O2 manipulator installs in line with the O2 sensor between the sensor and the ECU. It is a very small voltage regulator that you can manipulate via a small screw on the wire to adjust the voltage sent to the ECU "Tricking" the ECU into thinking it does not have enough fuel. WOW! as soon as I installed the manipulator on the Ducati it was a COMPLETELY different bike!
O2 Manipulators are an economical solution to alter the closed loop air-fuel ratio on many Ducati Motorcyles. O2 Manipulators are “plug and play” requiring NO cutting or splicing of wires and installs inline at the factory oxygen sensor connection. O2 Manipulators work by altering the oxygen sensor output voltage. This slight reduction in voltage forces the ECU to add additional fuel.

I am emailing fatduc now to see if they can make one with the connectors found on the 1200GS.
If you go to you will see a similar solution for Harley Davidson's. The approach is sound and takes advantage of the exact voltage characteristics of the stock O2 sensor. The ECUs are usually making the rich/lean decision at a certain voltage. The stock O2 sensor changes from rich 0.8 volts to lean 0.1 volts, very abruptly at a gasoline AFR of 14.7:1.

These devices, fatduc and nightrider, modify the voltage so that the switching conditions needed by the ECU get shifted in voltage. The only problem is that this approach doesnt work with every ECU. They are not highly accurate but if you want more fuel, and they make one that works with your particular ECU, you can get a very good result. If you dial these devices to say 14.1:1, 4% more fuel is added to closed loop, and through a slower process called Adaptation, to Open Loop also.

This is a very economical, technically sound approach if it works on your particular bike. With this approach you don't know how much fuel you've added exactly but you dial in more until you like the result.

If you want more precision and measurement capability, the Innovate Motorsports LC-1 allows precise programming of Closed Loop AFR.

In both approaches you need one device per O2 sensor.

roger 04 rt is offline   Reply With Quote