possibly bad crank seals? Im new!!

[Bones]

Hello, just bought a 2001 KDX200 from a friend. Love everything about it but I recently started having problems. To start, bike would not idle, cleaned carb, had to put needle valve clip on first notch to get it to idle. When riding for first 15-20 minutes, first gear is crappy, sounds like its loading up, wont come on the pipe. 2 gear and up while revving high it seems to "clean out" and runs fine. After 20-30 minutes of riding is when the real issue starts. At High RPM it cuts out like it cant get fuel, then it will rev high during idle and has all kinds of power in first gear? THEN it will usually rev to the freaking moon on its own in neutral with no throttle input!!! I mean it sounds like the piston is gonna shoot through the gas tank. Other Symptoms include smokes a lot and is leaking the black goo out of the silencer. I haven't ridden enough to notice the crankcase oil getting lower. I think I may have posted this in the place where I'm supposed to introduce myself, but I couldn't figure out how to put it anywhere else!! A friend suggested bad crankcase seals, so I'm looking for similar experiences for confirmation. Thanks

[KDXGarage]

Welcome to kdxrider.net.

How did you clean the carburetor?

I would suggest a pressure test and vacuum test.

[Bones]

Welcome to kdxrider.net.

How did you clean the carburetor?

I would suggest a pressure test and vacuum test.

Took the carb completely apart, used spray cleaner. Didn't soak it anything

[KDXGarage]

I would check the float valve. If it is running fine, then not, I would check fuel issues.

[bufftester]

First thing to do is put the needle valve back to the clip it was at and walk through the jetting guide. It should go without saying that you make sure that there are no other mechanical issues (cracked boots, missing clamps, clean filter, good fuel flow, etc) first. Moving the needle to affect idle is not the way you fix it, not even the correct circuit in the carb. Pull the carb, clean it again thoroughly with spray cleaner, and note the main and pilot jet numbers for reference. Set the float height (16 mm is stock, but most people get better results at 18mm) Then follow the jetting guide, never changing more than one thing at a time. Keep in mind that you jet the bike to a fuel and oil combination. So pick a fuel, pick an oil, pick a ratio, then don't change it (if you do you will need to run through the parade again)

[Bones]

I appreciate it, will pull carb off on Thursday and get back to you