Newbie question about stock EFI systems

[redShogun]

Good morning guys!

I have a question about the fuel injection system on my motorbike (Suzuki Address FL125).

Two weeks ago, I installed an aftermarket exhaust system (muffler + pipe) for my motorbike (exhaust brand is Motorsport, which is made in Greece) and I replaced the stock filter box, with a KOSO cone filter (35mm). It's a Euro 3 model, and the stock air filter and exhaust really choke the engine. I would also like to mention that my exhaust system is street legal since it's below the sound limit (dB) it produces and has a fixed silencer in it (sounds great actually).

The bike does in fact feel a little bit more lively to me when it comes to throttle. My question though is: does a stock fuel injection system actually recognize the change in air intake values and corrects the fuel-air ratio by itself, or do I need to tune it in order for it to inject the right amount of fuel for my aftermarket exhaust and air filter?

My motorbike uses Mikuni DCP-FI (Discharge Pump Fuel Injection) with a 24mm throttle body. The ECU is right under the riders seat and also the heated O2 sensor is located at the exhaust pipe. Furthermore, according to the service manual I have on my PC, there is a sensor at the throttle body which measures the air intake pressure and temperature.

I visited some tuning garages here and they all told me that the ECU on this bike can not be modified because "it's locked" as they say. There is also a Takegawa (Japanese brand) fuel injection controller which bypasses the stock injection time settings and allows you to choose for how much longer do you want the injector to inject fuel in the combustion chamber.

So, do I need to tune my fuel injection system, or it's not necessary? If there are sensors at the throttle body that measure the pressure and temperature of the incoming air, shouldn't the ECU correct the fuel-air ratio?

Thanks in advance!

[Gerontious]

Its a 125 step-through scooter.. its not going to have a sophisticated FI unit. stop overthinking. it will be fine as it is. Just enjoy it for what it is.

[dynax]

You would probably have to get an ECU that can be remapped but is the cost really worth it, most FI 125's are built to near enough their peak performance from stock, there are some things you can do to improve them but you will only gain marginal performance, and in most cases the cost outweighs the benefit in performance

[redShogun]

An aftermarket "empty" ECU like Ignitech V92 etc costs about 100€ and in order to map it it will take another 200€ so it's gonna be 300€ total cost. No no no. I prefer spending these 300€ to food and gasoline.

Then I leave it as is. Thanks guys!