GSXR 400 dropped a cylinder after carb rebuild

[computid]

Hi guys,
Got a bit of a problem. My bike was running a couple of weeks ago, I had it on the road. Some of you may have seen my thread about it cutting out when hot but thats something different I think. I decided to rebuild the carbs with fresh O-Rings and I was right to do so looking at the state of some of them in there! Anyway I changed all the O-Rings (I got a set from Variable Valves Suck) and reninstalled the carbs. Now the bike does start but only with the throttle held open (and the idle screw makes no difference) and its running on three cylinders with copious white smoke and fuel running down (!) the exhaust header of cylinder 2 when the bikes been run for more then a couple of minuites. It also doesn't seem to rev when I open the throttle more, just keeps running at the same speed.

I've removed the carbs and double checked the seating of all the O-rings and they seem fine. I've removed the spark plug and checked for a spark and sure enough there is a strong blue spark from it. I cleaned up the electrodes just to be sure and put it back in the cylinder, I will change it soon but I don't have any spares and I refuse to pay £9 for one at halfrauds.

So, does anybody have any ideas?

My current train of thought is:

Either a) The carb is flooding the cylinder and preventing spark, b) The spark plug is breaking down under pressure, c) The HT lead is breaking down or d) The coil has failed/is failing.

If anybody has any suggestions of other posibilities I'd appreciate them. It was certainly running on 4 before I touched the carbs.

Oh, and one other odd thing, when I rebuilt the carbs I checked how many turns out one of the pilot screws was, it was 2.5 turns out rather then 1.5, I've put them all back to 1.5 turns out but does anybody know why they might have been out more?

[CB 4]

HI are the float heights ok and floats undamaged also is it possible the float needles may be warn , does the bike have any form of emmission control system ? The mixture screws may have been set further out if if some one had modified the exhaust or air intake to richen/ improve the idle .reg c

[computid]

Thats a good point. It doesn't have any emissions control systems, but it does have a stainless steel 4-1 aftermarket exhaust system that I completely forgot would make a difference! I'll wind the pilot screws out tomorrow and see what happens.

Thanks!