Okay, first thing I´ve seen is that you use SoftwareSerial.
The standard Library does not support 10400 baud. It then takes the nearest value, which will be 9600 and does not work.
Where do you got the handshake sequence from? Using the K-Line and standard communication will require a startup message as hex, after your FastInit sequence.
How is you wiring? Do you use a L9637D?
But I´d first try to make an ELM327 work and ensure it´s doing what you need. Then start developing with the Arduino.
As I already asked, does the bike have the red six-pin diagnostic plug? Are you using an adapter or do you build it yourself?
I have a OBD Suzuki File from a 250R Suzuki around somewhere. I´ll take a look into it, when I found it.