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yz250 2 stroke oild comming out of exhaust?

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hi guys sry if this is a stupid question but my bike is a 1998 yz250 its running will well, but idles really high. i know theyre not ment to idle but i cant seem to idle it down. i do not know if this is causing the problem or not, but it is dripping black oil out of my exhaust silencer. its pooring out to the point il ride for 5 10 mins and the rear wheel will be covered in black along with back of frame. it also continues to drip out after letting it sit a little while. i have taken it apart and its covered in oil. the packing is soked please help!!!!! i do not know if this is something that is very ergent or not thanks guys.

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Maybe you are running rich, how is your plug? i had the same problem and was just exhaust packing and jetting, is not going to damage something but is easy to fix.

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With that amount of oil, I would bet your clutch side crank seal is leaking.... Replace both seals at the same time, since if the ignition side seal leaks you'll get a high idle from the air leak.

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I spent a good amount of time chasing this exact same issue down on my '94 YZ250. I did a bunch of things at the same time, so I'm not exactly sure what fixed it... but here's what I learned. Also, it is not uncommon that uncontrollable high idle is due to an air-leak in the system: cracked air-boot, bad gasket, clamp on carb is loose, etc. (Right now, I can tell you that if you do have a bad air leak, that will definitely cause your engine to burn funny = mass spooge)

1st: Reeds, make sure they're good. I was suprised at how much this helped. Even though my reed looked decent, they were just super old.

2nd: Right side crank seal (if it's sucking trans fluid, that's where it's sucking it from.)

3rd: Power valve: mine was gooped to hell and wasn't operating correctly. Just fully disassemble and clean real well.

4th, Finally: your expansion chambers is now full of that crap that came out of your pipe too. Clean it up. Repack the silencer, that packing is useless, and actualy hindering the system.

Good luck.

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well i did get it a couple weeks ago. The guy obviously did not take care of it. it didnt do this when i test rode it at his house, but i didnt ride it very hard. now that ive cleaned it up a little and put some new parts on itt cotes my rear wheel with oil now. ive also noticed sometimes when i kick it over i get a pop and the air will blow the drain lines on my carb off i try adjusting the carb acording to the new manual i baught for it and it seems to be better but will still do it every once and a while.

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i did have trouble starting it the other day it seems that it doesnt want to idle for long if cold. every time i try to let it warm up by idleing it floods the spark plug and i have to take it out kick it over without the plug in then clean the spark plug then install. then it will run for a little bit then die. i adjusted the carb to the settings in the service manual and it seems to have fixed that but thats when i started noticing the oil comming out of the exhaust, like dripping and covering my whole rear end. but it doesnt sound bad unless i put it in nuetral and let it sit then it gradually gets louder and louder i dont know if this is a characteristic of the yz250 or if something is wrong. would that still be because of an air leak?

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Did you replace the seals as the above posters mentioned? And check your reeds?

Both parts are very cheap and easy to get to and if the previous owner neglected the bike then they probably need replacing

However your bike def isn't running right, after you sort out the parts I just mentioned, you need to play with your jetting. There is a jetting thread in the FAQ, just follow that.

Seals, reeds, jetting, all very cheap parts just slightly time consuming (particularly jetting IMO)

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