I have a problem with my 1998 Kawasaki KX 250 from I bought it, the plunger/starter (choke) won't stay up when I go to start the bike even when the choke seems to be already ON, this is because when it does start the bike is running at a fast idle speed and sits ticking over, I haven't taken this bike for a run yet and I have her a while now because I'm afraid of doing damage and just start her on a stool to keep her right, I can't shut the choke off because the plunger won't stay up to begin with, I'm afraid if I take her out she'll wreak herself or keep flooding the engine, could someone out there "Please" help me and tell me how to cure this.
I've owned a '98 KX 250 before, unfortunately I never had that problem. I would suggest maybe you should pull the plunger out and take a look at it. There should be a spring on it that preloads it when you pull it up and twist it and when you twist it back to turn the choke off then the spring pushes the plunger back down. Find a parts diagram on any sight that sells OEM parts for your bike, pull up the carb assembly diagram and make sure all of your parts are there by comparing it to the diagram.