James, FYI, I am running a 40 pilot, 170 main and a big fat CGL needle at clip #4 in my 00 250EXC at the moment.
As you'll note, the main is lean relative to the settings in DRN's 250EXC wisdom collective, but I have tried richer mains right up to 180 and it gets slower, spoogier and has less over-rev with every richer step. Put it down to local fuel perhaps.
With the CGL, I occasionally get the much documented "KTM single event lean knock when rolling off the throttle" while riding through tight single track and not exceeding about 1/4 throttle. A richer transition from 1/8th throttle to 1/4 throttle would probably cure this. Low down throttling (less than 1/8th throttle) is very good - much better than the NOZI at clip #1.
My feeling is that KTMs are natural spoogers in off-road riding conditions, because even running very lean, they still seem to do it. I wonder if scavenging efficiency at lower revs and power valve adjustment affects the propensity to spooge with these engines.
I have not finished fine tuning this bike, but I thought I would post my findings so far.
- Grant
S