OOOOOOOOOHHH I have the fix for you my friend. It took me almost 2 years to figure this one out and a few $.
I replaced the spark plug wires, spark plugs, coil, twist grip sensor, gas, fuel filter and even repaired the wires and plug at the throttle position sensor and this misfire would just not go away. No check engine light and no codes. One day I was sitting with a old dog and I was telling him my problem and with out hesitation he said..................
Throttle body sensor is covered in oil, remove it, spray and clean with electronic cleaner and you will be ok. I removed it and yes it was covered in oil and dirt. I ended up buying a new one. I have over 200 000KM so I figured it was time. I guess we should listen to the old guys.
I tried to download some pictures but cannot resize them. If needed I can do them for you. Let me know.