I just wanted to say Thanks to all those who have contributed to this site.
About 2 weeks ago, I purchased a 2007 S40. It only had 2,400 miles on it, but it had sit for a year without being used.
I put fresh gas in the bike, and it ran (ideled) rough.
The first thing that I did was drill out the brass plug, and work with the idle mixture screw. I found the sweet spot, and it idled great.
I took it for a spin. It accelerated OK, but would not hold a steady speed (any speed) without stuttering.
I read the 'white spacer' article, and the various atricles on jetting.
I tore it apart today. Just wanted really say thanks for all the pictures and advise. Made the job much simpler.
When I went to remove the main jet, it snapped off. Upon closer examination, it had been cracked for a while, as the break was coroded.
I ground the white spacer down to 2mm. I buffed the slide on my buffer wheel (knife maker). I installed a new 150 jet. Did a general cleaning.
I set the valves, and found they were a bit tight. Put in a new standard NGK plug.
When I fired it up, it ran very well. Re-set the idle. When I came up off idle, it transitioned without a stutter. I'm anxious to button it all up, and take out on the road.
I changed oil. Used Rotella T6, and added Marvel.
All this made much simpler by all of you, from where to get a filter, to what type of oil and addative to use, to the diagonistics!