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KTM 2 stroke high idle or bogs out

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2013 250 xcw. All stock. All woods riding/new england single track.
TL; DR = when I stop it has high idle or bogs out, is it too lean or what does this mean?


Bike ran great all last season, but was acting up one ride recently. (VERY high idle when I stopped, fuel pouring out, etc.)
So I replaced the kinked throttle cable and took apart the carb and blew out all of the jets (one was gunked up, had been sitting for about a month)

All problems went away next ride - I thought all was good....

BUT Most recent ride, when I stop the idle is either VERY high, or so low it shuts off or bogs out when I touch the throttle. Became very hard to start-10 kicks instead of one. Runs great everywhere but idle/low RPM so I'm guessing Pilot related?
After doing some reading I assume it's too lean (has also gotten much colder here recently, but did run fine last fall)
But I don't get why its either very high or very low RPMs without touching anything. Are these both indications of lean? I assume I should start by messing with my air screw but I'm pretty new to carbs and tuning so any help would be great. Thanks!

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48 minutes ago, WILLY THE WORT said:

Age of top end ?  Low compression will do this

Last time you changed the crank seals ? You are supposed to change them with every other piston. That would also do that.

I was afraid of that. Hoping its less serious. Weird that it was fine last ride though.

PO told me he changed the top end 30 hours ago, but that's going off his word. No proof. Bike has 180 hours.

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2 hours ago, Puglia10 said:

I was afraid of that. Hoping its less serious. Weird that it was fine last ride though.

PO told me he changed the top end 30 hours ago, but that's going off his word. No proof. Bike has 180 hours.

OK, here's the thing; you don't HAVE to do scheduled services on your bike, but now look at all the time you have wasted.

There's a reason why the manual tells you to remove the piston and rings and measure them; so you will know just how much wear has occured, so you can guage what YOUR service intervals should be.  

I change seals every other piston, just to keep from being stranded, let alone from wasting valuable time.....otherwise spent riding.

Did you know a two stroke needs to have it's top end replaced at LEAST twice as often as a four stroke ?

It's a good thing you don't have a four stroke, as you would have probably blown it up by now !

 

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16 hours ago, WILLY THE WORT said:

OK, here's the thing; you don't HAVE to do scheduled services on your bike, but now look at all the time you have wasted.

There's a reason why the manual tells you to remove the piston and rings and measure them; so you will know just how much wear has occured, so you can guage what YOUR service intervals should be.  

I change seals every other piston, just to keep from being stranded, let alone from wasting valuable time.....otherwise spent riding.

Did you know a two stroke needs to have it's top end replaced at LEAST twice as often as a four stroke ?

It's a good thing you don't have a four stroke, as you would have probably blown it up by now !

 

Lol, I've had four strokes for 20 years and havent blown up one so I think I'm doing OK.

I get that I should check the top end or should have when I bought it, but it ran awesome and had no issues. Riding season is short so figured I'd just ride it and tear it down when the snow flies. I understand it could be a top end, but since it ran awesome the ride before this, I was thinking it may be carb related. Is there a better way to eliminate that possibility before I open up the engine? Would hate to do that when it was a simple carb/jet issue or something.

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If you  bike EVER ran will with the jetting it has now, there is NO REASON to expect a need for changing the jetting.........your symptoms are NOT jetting.........

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