need some help

I really need some help and some ideas please so here it goes.
I finally put the bike back together this past weekend and it starts fine but idles real rough like it is choking or something. Once you rev it up past 3000 rpms it like a rocket but once it drops below that it sputters and struggles to keep running.
Here is a little history on what has been done since the carbs arrived.
I placed the carbs (rebuilt by wired george) on the bike but the bike seemed to run on three cylinders. I had my dad come over and he checked it out and said that there was an intake valve sticking. So we tore it down and checked the vavles and sure enough #3 valve was sticking. Seeing the bike had very little miles but was in storage for a long time (not stored right either) we decided to have the valves lapped and everything cleaned in the head inside and out. We took it to the head guy who cleaned out all the build up and lapped the vavles for us. The seals were all replaced along with 1 vavle guide. We put it back together and set the shims to specs. All the spacing ranges from 125 to 152 so I should be good there. I replaced the carb holders (the others were the original). The cams are lined up with the timing marks and are good. I replaced the plug wires with new ones along with the plug caps. I have checked the voltage at the coils and it reads 12.2 (I also did the coil mod a while back on the bike.) I am not sure what else to check. I check for vacuum leaks by spraying wd-40. I do have the smog system removed but everything is capped and tested good. I have read and read through the manual but have no luck. I have also done some reading online but not having any luck. The bike is a 1983 kawasaki 750 ltd model. It has the mukini carbs that were built by you on it. Other than the coil mod and smog removal everthing else is stock.
Any suggestions would be greatly appreciated.

thanks,

allen

Have you checked the timing?
Sounds like it could be a bit retarded.

Since you said the bike sat for some time have you checked the mechanical advance unit(behind the ignition pickup) to see if it was sticking??? Check for vacuum leaks with ether or carb cleaner, wd40 may not do it.

Did it do the same thing when you had the old intake boots on???? Just cause you have New Boots, It doesnt mean they'll work. When checkin for intake leaks and so on, use carb cleaner. Think its called B-12 or somethin to that sort.