There you go Nate. Lots of things to look at.
An open comment directed at no one, but intended for everyone…
We make all these modifications, usually (incorrectly) all at once, in a kind of shotgun approach, based on what others have tried and/or what we know about tuning.
It's funny... I've had people PM me because their bike wasn't running right.
They’ve used jetting info for an '00, on their '03 and visa versa. They confused 4" Supertrapps with 3"... IDS2 data with stock (and modified stock) muffler data. Thought that a larger jet always would make more power than a smaller one... never factored elevation into the equation, made assumptions based on… more assumptions... and so it goes, and always will.
I based my tuning on the data acquired nearly 2 years ago by Flanny… who I know spent a good deal of time tuning and tweaking his bike. (How many of the current crop of 640 owners are aware of this?)
I knew that his 640 (an ’01 wasn’t it Flanny?) was not my ’03 640, and that the info that he had obtained was although very useful, was only a baseline for me to work from. Some of the information was near perfect verbatim, and some required further “tune and test” on my part.
What I’ve posted, repeatedly, was what I found to work on my bike, not every year of every 640 with a BST, ever made.
I hope I’ve made it clear, and I’m sure Flanny and most everyone else that has provided tuning information would agree, that the data is pretty much empirical… that everything we know is based on subjective data and not chiseled in stone.
It’s not rocket science… but it is science… and experimentation… and trial and error… and effort.
The people who benefit, should keep that in mind.
And before I close, I’d like to offer to Flanny a public “Thank You” for the work and time and thought that he put in a few years ago with his 640.
His efforts, and willingness to share, provided me with the raw material and a direction to develop the state of tune on my bike… and in that spirit, the willingness to share what I have learned as well.
We all have someone to thank... someone that came before and was willing to share... but we also must be mindful that information is not just what it is but, how it is used.