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Problem with Rough/Low Idle after WOT run

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So I went ride today and the bike ran great all day. Rode trails and never really got WOT. At the end of the day right before loading up i took the bike on a WOT run to "clear" it out. Ran and pulled good all the way through but when i got to 4th or 5th and WOT it stared sputtering like its rich on the main (it probably is). The thing that I couldnt figure out is after it started sputtering on WOT run, I pulled back to truck and it started idling low and rough and almost wants to die. Bike is 2017 YZ250x with 10 hours on it. Any ideas on what could make it idle low/rough after WOT run? Im definitely going to go at least one size smaller on the main but i wouldnt think the main would affect the idleing like it did. Correct me if im wrong. Thanks in advance

Edited by Dconer1

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I was having the opposite problem today. After fast runs my 16x was high idle almost lean surging. I'm going to go richer on the main.

 

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So I went ride today and the bike ran great all day. Rode trails and never really got WOT. At the end of the day right before loading up i took the bike on a WOT run to "clear" it out. Ran and pulled good all the way through but when i got to 4th or 5th and WOT it stared sputtering like its rich on the main (it probably is). The thing that I couldnt figure out is after it started sputtering on WOT run, I pulled back to truck and it started idling low and rough and almost wants to die. Bike is 2017 YZ250x with 10 hours on it. Any ideas on what could make it idle low/rough after WOT run? Im definitely going to go at least one size smaller on the main but i wouldnt think the main would affect the idleing like it did. Correct me if im wrong. Thanks in advance

What temps are you riding in?

If it is cold & the jetting is stock, the engine may have been hurt.

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What temps are you riding in?

If it is cold & the jetting is stock, the engine may have been hurt.



Temps were 70-80F yesterday. Current jetting is

NEDJ clip 2, 175 main and 48 pilot.

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Anyone else ever had this happen? Could it be a fouled plug possibly?

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Well, you have got to start somewhere in troubleshooting this. 

I would suggest pulling the plug and sticking a new one in. Then I would pull the carb and check for anything unusual. Maybe some trash made it's way into the bowl and is obstructing something.

What does the filter look like?

What position is your idle screw in? 

Is anything obstructing the exhaust?

You need to start by going over everything and look for anything unusual. Heck, I've even heard of jets falling out down into the bowl. 

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first thing im going to do is change the plug. when i pulled it, it was pretty black and it was a plug i put in that morning. I did a lot of lugging and it was loading up a little. Its weird though. It seemed to run fine lugging around and only acted up when i got on WOT after riding all day. the filter was clean. I think my air screw was about 1.5 turns out and there is nothing blocking the exhaust. Im hoping it was just a fouled plug and I need to lean out the pilot a little and the needle. last time i went to a 45 pilot though, it had a slight lean bog when i cracked the throttle. Thats why i went back to the 48. But now im thinking the 48 may be too rich with the low rpm riding that i do.

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