Fuel mixture 1998 ? - 1998 kawasaki KDX 200

Improper fuel/air mixture, possibly plugged up air filter?
You have 2 out of 3 of the needed components for that motor to run, and assuming your timing is correct and you have compression, it could be an air intake issue.

High HC counts are due to a rich mixture, too much fuel. How does the truck run normally? To adjust the fuel mixture at the carburetor, make sure the truck is at operating temperature. Turn the idle mixture screw clockwise until the engine starts to lag then turn the screw back just until it runs smooth. Also make sure you have fresh oil as this could cause high HC's as well since fuel gets into the oil and make sure your PCV valve is operating correctly. If you can't get it adjusted correctly, you may have to pay a shop to hook it up to the emissions machine to get the mixture correct, unfortunately.
Hope this helps. Good luck!

Could be a lot of things, but not holding rpm's can tell you a few things. I would do a few basic air/fuel mixtures test.
1. Check fuel pressure on fuel rail
2. Check Dirty Sensors( o2, Maf, Coolant, Air Temp), all these matter in the fuel air mixture.
3. Vacuum Leaks

adjust the air to fuel mixture there is 2 much air going in and not enough fuel on the carb there will be a screw there are 2 one which is the mixture screw and one for the idle the idle will be the one sticking out more than the mixture screw

There are two causes of your problem that I can think of: firstly, it may be that you, even after changing some jets, haven't got the air/fuel mixture right. If i were you, I'd put the standart jets back in, set the needle position to the middle position, and screw the air/fuel mixture screw 2,5 rotations ( 900 degrees) out from fully screwed in. This should return your bike's mixture settings to approximately standart. Then, using this page http://www.dansmc.com/spark_plugs/spark_plugs_catalog.html
determine if you have a rich or a lean mixture, and adjust accordingly. If you have any more questions, or would like me to clarify something, please ask.

could be Fuel Injectors, are bad ?
all you need is # 1 Fuel Injector, to go out that will not get Fire, and Fuel Mixture to Spark Plug.

sounds like your drawing moister change the dis cap prob has a hair line crack in it!!!

this can be done by buying a plug in tested \programer from a local auto store

I’m happy to assist further over the phone at https://www.6ya.com/expert/james_1cb31da1bc8c6102