Looking for some help with my son's Kawy. Anyone here help?

So my son is having problems with his bike. It seems no one on the kawy forums have an answer. I told him I'd post here seeing there seems to be a lot of mechanical knowledge here..but with Kawasaki?
Here's his post:

Motorcycle mechanics .. ZX6R 636 Gods .. lend me your voice!

My bike has gotten to the point where I have no desire to ride it. At a stop/idle, the bike is surging very badly, and the result, when taking off from a stop leaves many things to possibly happen...

- Bike falls on its face (doesn't go anywhere), then lunges forward
- The bike basically "hops" forward
- Seems to want to stall, even at like 2500RPM's, then randomly gets power to go

...etc

It makes me feel unsafe riding the bike because every stop sign/red light, I never know how the bike is going to react.

I took a video, and around 2:08 you can see the RPM's fluctuate randomly up about ~400RPMs and you can hear the bike just surging on and off.

Another note in the video is that my cam chain is still loud even after the shop installed the APE CCT. They claim the guides are worn down, so they couldn't tighten it anymore.

So my question to you guys! Why is the bike acting this way? Did the cam chain possibly jump a tooth? I don't hear valves hitting or what not, only the cam chain .. but DAMN, I don't want to ride this bike with it acting this way!

I'm gonna take a shot at this. leaking intake boots. Get a can of ether, spray it around the boots while the bike is running on idle, if the idle goes up there's you problem. I also ran into another problem on a ZX 600 ninja where the intake valve shims were worn, kinda the same symptoms. Good luck, wayne

what year is it,did it start after the shop worked on it.dont know your skill level or the tools you have but i would check for vaccum leaks,fuel pressure then timeing

plugs, wires, fuel pump (maybe getting ready to go out), intake boot, bad programming, any number of gaskets or whatnot could be effecting it

check ur battery connections; fouled plugs, intake leak, vacuum test to check carbs, leaks; clogged jets, bad gas,,,

Good ideas. Thanks guys. Some have been checked. Others need to be. I'll post up when problem is solved.
Thanks again for your input.
-Mike