Re: 99 CBR 900 RRX running rich...?
My manual says 2 turns out as initial setting. 2 1/2 (give or take) is the usual standard for all carbs I've worked on. Your plugs would suggest a few other things to look at.
OK, this is the procedure I would follow.
1. Is the choke returning fully, the operating bar can get crusted in crud.
2. Are the floats set at the right height (but if this problem is over all cylinders I would not initially be looking here).
3. Are the floats working properly, no flooding through bad needle valves. Again unlikely over all cylinders.
4. Are the pilot jets correct size.
5. Blocked airfilter. Although this does not usually affect tickover running to any great extent.
The Kei Hins fitted to Hondas are a far more reliable device than the Mikunis fitted to Yamahas, and are not usually beset by these problems. One thing I have found to be vital on Mikunis for tickover reliability is to ensure the rubber O ring on the tip of the adjuster screw is fitted and in good condition. To be honest, I dont think I ever took my pilot screws out so I can't be sure that yours actually have this sealing O ring fitted.
What I would like confirming is:- Is your engine breather hose 'pumping' gases and to what level.
Are you absolutely certain that your oil level is correct? This might seem elementary and I apologise if you have checked, but I have seen bikes filled to the upper oil level in the window with the bike on the sidestand. This will overfill the engine by a large margin, leading to oily gasses from the breather, straight into the carbs, MOST noticable at tickover / low revs.
A tool I have found invaluable for setting up pilots jets is an INFRARED THERMOMETER. Get a cheap one, but capable of reading up to 1000 degrees F. Along with a vacuum gauge, this allows you to balance carbs both for evenness of running AND for even cylinder temperiture. Adjust the pilots untill you get each cylinder within a few degrees of each other DISREGARDING differences in screw setting. Each cylinder works slightly differently so there is not a one setting suits all adjustment.
In your case, I really dont think that there is much amiss. Just to confirm, I would get it warm and do a few high rev passes and then inspect your plugs. If they are still dirty then report back.