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I am trying to get my bike to run properly and am totally lost!

I have a kx250 2001 model, was imported from USA believe from Ohio, and i live in Calgary which is 3500 ft above sea level, have striped the carb and found following>

Main jet> 145

Pilot>45

needle jet is set with clip on second position down.

the bike will not idle well unless have choke open or partially open throttle, if let off throttle when riding will die and is definitely running rich, plug is black and will gum up so cant start and back oily exhaust.

i have tried adjusting air screw but seems to make no difference and cant get it to idle properly to hear if airscrew is actually doing anything?

what do I do??????:smirk::smirk:

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If you go by Ohios lowest elevation point of about 450 ft. you can see you went up in elevation by at least 3k ft.. You most likely need to rejet leaner. The air screw is a good indicator of that if it can't lean things out enough at 3 turns out.

Leave the needle position alone. Replace the pilot jet first and with the air screw, get the pilot system dialed in first. Then work with the main jet to get mid and top end dialed in.

Be sure to check/set float level while you have the bowl off.

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am going to re pack exhaust as packing was very clogged with oil/gunk and have drained fuel, gonna buy better quality mix oil and re mix it.

would badly mixed fuel/exhaust problems cause above symptoms???

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am going to re pack exhaust as packing was very clogged with oil/gunk and have drained fuel, gonna buy better quality mix oil and re mix it.

would badly mixed fuel/exhaust problems cause above symptoms???

By all means, replace the exhaust packing. A gunked up exhaust "will" impede flow.

But a 2 strokes jetting is very sensitive to the kind of elevation gain you took it to. I don't see you getting around needing to rejet it.

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the one thing that is still confusing and correct me if I have got this wrong....

I have gone to a higher altitude and therefore air is thinner and so if anything the bike should be running lean, not rich???

could it be that wont idle as is too little air so need to increase main and then maybe running rich on the pilot side as get the bike moving??? :smirk:

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Higher altitude means you are getting less air and the same amount of fuel thereby making the bike run rich. You need to lean the bike out assuming it was perfectly jetted for the lower altitude.

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Any time someone is talking lean or rich, you're always talking about the amount of fuel in the air/fuel ratio. So like William said, when you go up in elevation the air is thinner/less O2 given the same jetting. You're still getting the same amount of fuel, but less O2 to mix with it, so you're rich(too much fuel).

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DOH!!!! :smirk::smirk:

I just re read my post about going up in altitude and air getting thinner therefore making it run leaner....what a dumb ass!!!

see i told you i was totally confused!!!!

thanks again guys.....

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