99 Bandit 1200 performance problem

[Mr.Ice]

Hi all, I would like to introduce myself. For the purpose of having a unique screen name I chose Mr.Ice. Believe me I do not think I am cool, it is just a play on my real name, which by the way is always taken. Any how I am looking for some help. I have a 99 Bandit 1200 and have owned it since new. It has 8000 miles on it and has been taken care of and is like new. It is all stock except for a Yoshimura slip on. I started the bike for the season a couple weeks ago and it ran great. I rode it for about 5 miles and it ran well through its entire range. Unfortunately I had family obligations and had to park it. The next time I took it out was about a week later and seemed to run well enough but when I tried to get the engine over 2500-3000 RPM it completely shut down until I completely let off the throttle and babied it back to life. I found the choke slightly on and turned it completely off and thought that was it. Not so, it continued for the 4 mile ride back to my house. I took the Bike to a local shop (Yamaha, I know but it was close enough for me to ride it there) and without even looking at it they wanted to tear the carbs off and clean them for $570. I decided I would do them since I did them once before and it was tooooo much to spend. I was not convinced it was to problem either. The bike was parked for the winter but I did use stabilizer in the fuel and it was just running great. I decided to pull the plugs. They were all covered with carbon.I put in new plugs. Now it runs a little better.I can get to around 3500-4000 RPM but then the same happens. Pulled the plugs again and all covered with carbon. Oh yeah it has black smoke when it is stalling out. Seems like a rich condition to me rather than blocked carbs. Can blocked carbs cause the carbon on the plugs? I am thinking it is ignition related, like maybe weak spark. Any help or advice is greatly appreciated. I would like to avoid pulling the carbs if I don't need to.

Mr.Ice

[seruzawa]

You can check the spark by pulling a plug lead and putting a spare plug on it, touching the base of the plug to the cylinderhead and cranking the engine. you should have a nice blue spark. Be sure to wear rubber gloves or else you might become ground.

[sarnali2]

If it ran great the first time you tried it then it's not a major problem. You say you left the choke partially on? I'd say use penetrating oil on the choke rod and exercise it a few times. I think your choke is still on or you've got a stuck float. Try completely draining the carbs and tap each one with a screwdriver a few times with the drains open. Use the prime position on the petschlonger and give them a good flush. If you had stabil in the tank you should be in good shape as far as that goes.