Man,..I wish I had a solid answer to that. I think fuel may be a very good part of it, also I think its simply a matter of perspective of how "good" our bikes run. Since we have to tune according to how good they run instead of plug color because of the new cleaner style fuel nowadays.

Maybe those two things combined simply how the air is...maybe all air is NOT created equal despite elevation and humidity. I dont know though, something tellls me thats not good enough reason. I mean, if I brought my bike to your house and rode..I just get the feeling it would run the same way it does here.

Like identical twins...even the same DNA doesn't make them the same.

 

When you speak of jets here what manufacturers are you talking about? They're arent all the same. I'm about to go 1 up to dynojet 132 from their 128 because my bike is still stuttering and being a little bitch.

 

the PO whent from the stock 118 keihin to a RD 130 (which is un upgraded Keihin as I understand it) not sure what brnad the 40 pilot was as i dont recall seeing anything but the number on there