Hard to turn mixture screws

[Fudd]

My '98 Tourer is running rich in the 3 to 4k rpm range following the installation of Dynojet needles and springs.
I just about rounded out the flat side of a cheap brass ebay D-bit mixture tool without even budging the adjustment screw on the 1st two carbs that I attempted.
Why are they so tough to break loose?  Is this normal?

[98valk]

probably frozen/corroded. I have same problem on one carb of mine.
anyway 3-4k rpms is the needles, not Pilot jets/idle mixture screws.
raise the needle clip one notch to run leaner

[sandy]

Dyno jet says the 3rd notch down from the top but I switched to the 2nd notch and get 37+ MPG. Spray some PB Blaster up into the pilot screws. When you can move them, remove them and put never seize on the threads.

[Ricky-D]

Did you get that, what CA said.

Messing with those idle mixture screws will yield no results whatsoever.

No to mention all the possible unanticipated consequences of attempting

to adjust them.

It's your Dyno-jet kit that's the problem. Thinking you'll achieve some kind

of performance enhancement with that kit is pie in the sky. Utilizing that kit,

you will be lucky to get back up to stock configuration performance.

***

[quexpress]

Quite a while ago, Patrick posted a tip about cutting a slot in each of the pilot air screws in order to be able to adjust them with a flat screwdriver.
I did ... and have never fiddled with these D-shaped mixture tools again. 
Thanks Patrick! 

[Fudd]

Thank you everyone or your responses.

I researched every applicable post that I could find before deciding to change a perfectly good stock exhaust system for a set of Cobra 6 into 6 pipes a couple of years ago.

I made the switch, full well with the knowledge that I may loose as much as 8 horse power with the modification.

Maybe the condition was already there, and maybe the condition became more pronounced, but I noticed a significant loss in midrange to upper mid range power.  However, at around 5200 rpm this bike would jump like I hit it with nitrous and a cattle prod at the same time all the way to red line!  As a matter of fact, I learned to ride it that way.  My 2-stroke race bike experiences kicked in allowing me to keep my rev's in a tight "powerband." 

It wasn't until I rode nephew's Tourer that I saw how bad my bike was performing.  He has 6 into 6's also, but he could eat my lunch from idle to red line!

As part of a purchase of assorted Valkyrie goodies, I have had an unopened Dynojet kit sitting on my shelf for several years.  I was not expecting an "enhancement" of power, but was hoping for the possibility of a normal power  curve when I decided to try the DJ needles and springs.

What I actually found to be my problem, was a totally deteriorated carb vacuum slide on the last cylinder that I was working on.  Replacement of that defective part TOTALLY eliminated my midrange lug.  But, my engine now runs to rich on  lower midrange rpm's.

I'll move my needle clips per CA's recommendations tomorrow.