82 Z250 LTD carb help

[couchflyer]

I am trying to get this bike running good for my son's friend.  It was sitting for 3 years.  The carb is vacuum operated.  I cleaned it out twice.  I can get the bike running however it runs rough between 1800 - 3500 rpm.  Above 3500 it runs great.  I think it might be a plugged jet.  

On idle the bike not run unless the choke is on.  I can pull the choke off only when the engine is warm.  

Any ideas?  I'd like to trash the vacuum card but don't know what its replacement is.
Thanks

[Brayon Rider]

With the info you give, sounds like a plugged pilot jet. This jet is located right besides the main jet (when the carb is turned upsidedown, and the bowl is removed). The pilot is approx. 3/4 of an inch long and screws in.
All you need to do is remove it and blow it out, hold it up to a light and you will easily know when it's clean.
Before you remove the carb from the bike, remove the intake booth and see if the slide is operating when the bike revs up. This will verify the vacuum portion (diaphragm). A small mirror may come in handy to able you to see in better.
You may as well clean the rest of the passages while the carb is all apart.

[couchflyer]

Thanks, I'll clean it out this winter on a bench paying attention to that pilot jet.

[80G]

Try to find wiredgorge on the  http://kzrider.com/  He also has a page at http://www.wgcarbs.com/index.html