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Yz85 bogging/losing power

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Hey guys i bought myself an 04 yz85 4 weeks ago, so far its great except for one thing i noticed, a bit after i hit powerband in 1st, 2nd and 3rd gear it starts to lose power almost as if its not getting fuel or spark, in 4th 5th and 6th i haven't noticed it as much or at all, could it be my jetting? A sparkplug issue? The air screw was pretty far into the "hole" and was filled with oil, had to dig it out just to see the screw, as far as i know the jetting is stock but i am the third owner so im not sure, its has an fmf powercore 2 silencer, i get a little bit of spooge but not much, runs a stock ngk brg10eg, last time i checked it, it was a bit wet and a darker brown, not quite black, ive read it could be the stator not giving enough spark? Or possibly an exhaust leak? Dont really have a clue what it could be, please help me out, dont think its the engine as it was rebuilt about 8 hours ago.. Thanks for any help, sorry if i didnt give a good description on whats happening but i cant really explain it, almost seems as if the clutch is slipping? 

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If the clutch was slipping it would scream and not move. Lightly screw your air/fuel down til it stops, then turn it out 1 1/2 turns out, if that doesn't help come back!

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6 minutes ago, Smoking 2's said:

If the clutch was slipping it would scream and not move. Lightly screw your air/fuel down til it stops, then turn it out 1 1/2 turns out, if that doesn't help come back!

Ah ok its not the clutch then, Turn it down till the bike shuts off? Out of fuel right now but ill try that tomorrow and see if it helps! Thanks for the input 

Edited by Braapstustu

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1 hour ago, Braapstustu said:

Ah ok its not the clutch then, Turn it down till the bike shuts off? Out of fuel right now but ill try that tomorrow and see if it helps! Thanks for the input 

That's not what I suggested at all.

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2 hours ago, Smoking 2's said:

If the clutch was slipping it would scream and not move. Lightly screw your air/fuel down til it stops, then turn it out 1 1/2 turns out, if that doesn't help come back!

"lightly screw it down til it stops" sorry did you mean until it stops screwing further in? I Misunderstood i apologize. 

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Bike shut off, screw in the air mixture screw til it lightly seats, then turn it back out counter clockwise 1.5 turns. See how that does, if it's way off that will cause rich or lean conditions. Report back after

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20 hours ago, Smoking 2's said:

Bike shut off, screw in the air mixture screw til it lightly seats, then turn it back out counter clockwise 1.5 turns. See how that does, if it's way off that will cause rich or lean conditions. Report back after

Alright so i took the spark plug out to see how it was before riding, a bit wet and bit black, so i cleaned it off and road for maybe 15 minutes, then i shut the bike off and the air screw was only half a turn out! So i turned it 1 1/2 turns out as you said, and the bike wouldn't start, kicked it over maybe 20 times and held the throttle wide open for the last kick when it finally started, but as soon as i let off the throttle it died, started it again and was just revving it for a minute ti see if it could hold an idle, shut the bike off and noticed oil was spewing out the exhuast and where the expansion chamber meets the silencer, not a few drips! Litterally spewwing out like a fountain, the rubber "gasket" that covers that joint is toast, ripped and shredded, so now my bikes covered in oil, what does that mean? I was running wayyy too rich when i let the air screw out? I am clueless, is it jetted too rich hence why the air screw was so far in? 

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Your air screw should be between 1-2 turns out, cleaning off the black stuff off a plug doesn't necessarily make the plug fire better! How do you ride? If your putting around it will build oil in the power valves and once pegged will have to blow out somewhere! If your air mixture was that low maybe your idle screw was also changed, so once running you may need to adjust idle also. If no cure there you'll have to pull carb and clean and check reeds and compression while your at it.

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10 minutes ago, Smoking 2's said:

Your air screw should be between 1-2 turns out, cleaning off the black stuff off a plug doesn't necessarily make the plug fire better! How do you ride? If your putting around it will build oil in the power valves and once pegged will have to blow out somewhere! If your air mixture was that low maybe your idle screw was also changed, so once running you may need to adjust idle also. If no cure there you'll have to pull carb and clean and check reeds and compression while your at it.

I dont ride too hard but i definitely get on the pipe quite a bit, and its a yz85- they dont have a power valve. Ill definitely pull the carb yet and check my jets etc, but it only started spewing oil once i screwed the air screw further out, why is that? When it was at 1/2 turn it spooged a very minimal amount. Do you think itll run "normal" again if i put the air screw back how it was? Really need to ride this weekend. 

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On 6/7/2017 at 5:30 PM, Braapstustu said:

I dont ride too hard but i definitely get on the pipe quite a bit, and its a yz85- they dont have a power valve. Ill definitely pull the carb yet and check my jets etc, but it only started spewing oil once i screwed the air screw further out, why is that? When it was at 1/2 turn it spooged a very minimal amount. Do you think itll run "normal" again if i put the air screw back how it was? Really need to ride this weekend. 

Can anyone help me out? Or give me a clue as to why it started spewing oil as soon as i put the air screw 1 1/2 turns out, compared to 1/2 turn out when it ran fine, except it would bog in powerband in lower gears. 

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20 minutes ago, Braapstustu said:

Can anyone help me out? Or give me a clue as to why it started spewing oil as soon as i put the air screw 1 1/2 turns out, compared to 1/2 turn out when it ran fine, except it would bog in powerband in lower gears. 

Zero chance, air mixture screw affected the immediate spooge, pilot jet affects the first 1/4- needle affects then til 1/2, main affects the rest! I'd love to help you but this whole thing seems fishy.

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24 minutes ago, Smoking 2's said:

Zero chance, air mixture screw affected the immediate spooge, pilot jet affects the first 1/4- needle affects then til 1/2, main affects the rest! I'd love to help you but this whole thing seems fishy.

Ok maybe i am very much mistaken then, is that not the air mixture screw that the screw driver is pointing to in the picture thats what i was told, and thats all that i adjusted, i have a new bp5es spark plug laying around would it help at all? I feel like its too hot as im running a 10 now.... Sorry i don't know what else to tell you, im not too good with carbs/2 strokes. 

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