KZ 250 carb question

I have a 1980 kz250 that has only 3500 miles on it. It has sat idle a lot of its life.
It runs well but I need to run it on almost full choke for several miles before I can take it off. Then it still doesn't seem to get enough gas at full throtle.
I'm assuming that it may have some crud in the carb.
I'm an experinced mechanic but have never had this carb or one like it apart.
If I take it apart to clean it will the passages to clean be apparent or are there hidden ones I might not see.
Any other good advice for me on solvong this problem?

Thanks, Al.

just thoroughly clean every hole you can find and if it has a vacuum slide(dont know the 250) look for pinholes

The article here www3.sympatico.ca/g.boudreau/CarbCleaning.html has some pretty good tips. Take lots of time. I use bristle from a brush to poke through the smaller holes. Some people use wire but this is controversial. There may be some very tiny holes. You just have to take your time and look for them. I have found the spray carb cleaner very good. USE SAFETY GLASSES. I cant say that enough when using the spray because you can shoot it down one hole and it will shoot back up in your face from another. When you have cleaned everything out with the carb cleaner take it to the local filling station and blow it with compressed air until you get bored. If you have a manual great. If not then go to www.kawasaki.com owner info, parts diagrams etc and you can print off a diagram of your carb which could help.
If you decide to soak the whole carb watch out for the rubber bits as most carb cleaners will eat them.
Good look and again take lots of time.

Thanks to all for the good info.
I sprayed carb cleaner down the fuel intake, cleaned the bowl on the shutoff and put in an inline filter.
It works much better now.
Al.