The poor off idle response is due to the lean settings necessary to meet Euro 3 emissions. The stock ECU runs off of a narrow band 02 sensor that controls fueling at low rpms and is set too lean. You might be able to smooth it out a lttle by making sure that your throttle bodies are properly syncronized/balanced but you will still be lean.
For good performance you need a CO level of 4-6%, stock is about 1.5%. Unfortunately, it isn't possible to adjust the fuel trim on the stock bike. To achieve 4-6% you have a couple of options:
- Get a DP ECU that eliminates the 02 sensor and adjust fuel trim to 4-6% CO out of each cylinder.
- Retain the stock ECU and get a rapid bike 02 emulator. The emulator does provide for some fueling adjustment and by itself, may produce good results. This is probably the least costly option.
- With the stock ECU and 02 emulator, add the Rapidbike 3 unit. This allows for remapping the fuel for each cylinder and ignition advance. This combination gives you more tuning options. RB has a canned map available for the stock HM that should work well.
For more info on the Rapidbike 02 emulator and RB3 unit, contact Al at
www.moto4us.com