Here's my experience...
Firt off, Les' service is great. Though I think it's hard to describe what is going on with the bike over the phone so that he can give solid feedback. Sometimes I think I just need to take it to him so he can ride it himself (I'm close enough to actually do that).
My bike wouldn't even run when I got it. It wouldn't idle at all, and even when opened up ran like crap. I put in Les' kit and adjusted the pilot and idle screws per his instructions and I had a running bike. I live in Portland, OR which is essentially sea level with 70 - 90 degrees in the summer.
I had some problems with the bike stalling on down hills. Les recommended adjusting the floats. That seemed to fix the problem.
However, somewhere along the line I changed oils (I went from using Torco to Mobile 1) and started having problems with the bike not wanting to idle clean and needing to be reved out a bit. I've leaned out my fuel mix a bit (I am now running 44:1, I was at 40:1), as I was getting more smoke than I wanted, but still have the idle problem.
I don't notice it when I am riding. The bike responds fine, etc at low and mid throttle settings. Sometimes I feel like it's a little off on top, but I rarely ride there, so can't say for sure.
In any case, whatever I would like to improve isn't bothering me enough to spend the time to mess with it.
I won't say my bike is jetted perfectly, but I think it is close, and Les' kit was a huge improvement over stock.
I'm considering trying the divider plate from RB as it sounds like it may correct my problem. Maybe I can get Ron to give me his impression on my jetting as well (he's even closer
). I'm not sure if I want to try that first, or go with the head mod Erik K. raves about.
One or the other is coming up soon. I have some downtime between enduros, so now's my opportunity to get some work down. The Black Bear enduro is in November. It'll be slick NW clay for 50+ miles. I'll need all the throttle control I can get at low speeds. I'm also going to try a trials tire for the first time.
Stay tuned....