carb issue

Hey guys,
My buddy just bought a 1987 ZX1000 and is having trobles with the carbs. I am not that familiar that year of bike,so I am asking you for some help to relay to him.
The problem is: the bike will run at idle and rev to around 6,000 and cut off,then back to idle. It has 36mm Keihin carbs on it and he says there is a vacuum piece or pieces that my need to be replaced. Somewhere around 100 bucks a pop!! If you can give any insight to this,please give all you can. It is his first street bike so he really wants to do the work himself,that way he knows about his bike.

Thanks,
Mike

Sounds like it could be torn diaphragms. If so, replacement is generally the best option. Yes, they are expensive. If this is the problem, then it is very likely that some ham-fisted goober has been in the carbs, so there is no telling what else could be going on in there. Good luck.