That mixture screw is on the right side of the carb its covered with a plug you have to drill a small hole then put a screw in the hole and pull the plug out. Turn the screw cc clock wise to richen.

At light throttle, 2nd gear, 30mph, just kinda loafin down the street, mine surged quite badly. W/ the choke on 1 click it ran perfect.
I elected to raise the main jet metering rod just a touch, like about 1/16th,....or .055 (normally called the white spacer mod)
After the mod it runs perfect,.....if there is such a thing.

Routy, according to the article on the said website I'm thinking your suggestion is the fix.  I'm guessing I might be able to get the top of the carb and diaphragm/slide out to raise the needle w/o removing the carb, no?

Savager wrote on 07/30/10 at 22:55:32:

I did the white spacer mod w/o removing the carb.
I elected to do the metering rod adjustment because from info I got here, this rod used to be slotted adjustable, till the EPA started dictating fixed carb adjustments.
But yes, do make sure there is not something else causing the lean condition before you make adjustments.
And a caution,...if you ever do the white spacer mod, do not mess up the heads on those 2 little bitty screws ! Get a brand new flips driver and a heavyweight guy to lean on that driver,.....or get Lancer's (HF) mini impact driver.

Don'tcha just love Lancer's carb details !

Lancer, I hear what you’re saying, and I neglected to mention the petcock was accidentally on pri (reserve) when I was making the mixture screw adjustments; maybe that would make a difference?  I was also considering that the pilot jet may need to be enlarged (or have “bleeder” wholes if the size that’s in there doesn’t already).
Here’s what I ended up doing that seems to have helped roughly 80% of the problem.  I was able to get the jet needle out w/o removing the carb (ralfguy it takes determination and a little skill, but it’s entirely possible and the tab that holds the throttle cable— on the front left screw— is a little in the way; I didn’t reinstall it after I removed the diaphragm assembly)
I found a little black washer I acquired from the hardware store (I think from the plumbing section) left over from a DIY jet kit (not some overpriced Dynojet) I put in a GS500e years ago, but it is only .03” not the .055” in thickness of Routy’s, nevertheless I put it under washer “B” [“B” being the small metal washer and “A” being the larger nylon washer] with little improvement as the result.  Therefore I decided to swap washers “A” and “B’s” position on the needle, keeping my black .03 paired with “B”.  I figured the worst case scenario is it’d run like trash, but lo and behold it seems that once the bike is warm it runs just like it does with the choke out a notch.  That’s right that big fat nylon manila colored “A” washer has become my “white spacer mod” for now at least.  IT FEELS RELATIVELY GOOD TOO, with just a slight slug or surge that really is hard to notice, but accounts for the remaining %20 of the problem alluded to earlier.  However I still have yet to adjust the pilot screw in accordance with the 2 paragraphs under “Pilot circuit; 0 to 1/4 throttle” section from the article on the website I posted earlier.  Hopefully I can dial it in and be done.  If not the carb will have to eventually come off, be cleaned and perhaps even a larger pilot jet order from someone, but not Dynojet especially since they only list years “00-10”.
Thanks for all of the help and illustrations.  I’ll definitely follow up on my results of the air mixture tuning later on today to see if that heals the issue entirely.
TIA for any more interaction/suggestions.
PS I was unable to post a diagram of the needle and washers A & B to help explain myself more clearly.  Is this because I’m not a “Full Member” or “Serious Thumper”?   Thanks again for the help.

"so you were able to use the black washer to lift the needle a little and richen the midrange and gain some performance."

Actually I used the stock nylon washer that's already in there; instead of it sitting on top of the circlip it now resides below it thus having raised the needle substantially [maybe too much?].  The black washer [along with the metal washer that used to sit between the circlip and the spring] now sit on top of the circlip where the stock nylon washer used to be before I moved it below the circlip.  This may've been a bad move, but it seems to have made an improvement for now.  I still haven't had a chance to really dial in the mixture screw which will help me know if it was the right change.  I hate stinkin’ carbs!  I know they're cheaper and lighter than EFI systems, and I think less prone to attributing to engine overheating though.

I put all 3 washers under the circlip and still the same 80%, I'm guessing the pilot jet needs to go up a size since cruisin' speed is at about 1/5 throttle, and that's were the subtle stumble is.  Any advice is still appreciated.