Loss of Power at 30

[Bun-bun]

I went and checked out Kris' bike this afternoon. My buddy borrowed my maual, so I just did some basic checks.
Bike stutters at about 4500 RPM.
Bike is running rich.
Horizontal plug showed rich, and had a minor amount of oil around the threads.
Stuttering seemed to get less noticeable as the bike warmed, and it was ridden.
I added Techron to the fuel in the tank, and told him to run it for about 20 miles to mix everything up.
Now, My questions:
Would water in the fuel cause the 'puter to adjust to a richer mix?
Would that readjust once the fuel coming in goes back to straight fuel?
How would I get the 'puter to start runnin gleaner.
Bike is an '02 620ie. Completely stock except for a pair of chopped, cored cans.
Any help appreciated.

[metallimonster]

I just had a very similiar problem about a month ago and a half a bottle of heet cleared it up in about 15 minutes.  I would suggest trying that if you think you are riding in the correct rpm ranges.  I was very surprised at how well it worked.  I thought for sure something else was wrong. 

Try some heet.  Fuel injector cleaner won't do the trick.  I don't know about mixing the 2 so you might just want to drain the tank and start over with a little bit of heet in it.