Carb question

kx254f
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kx254f
Edited Date/Time 1/19/2012 4:30am
I have a 2009 KX250F with a Pro-Circuit top end. When I am twisting the throttle both riding or in neutral, the bike bogs a bit before it revs cleanly. It seems to do this when I twist the throttle quickly. Is this a jetting issue? Air/fuel issues?

Any help is appreciated. Thanks in advance.
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MOTODAD422
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MOTODAD422 10/15/2011 11:59pm
10/15/2011 11:59pm
What size pilot jet do you have in it. 40-42-45 ?.
kippy450
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kippy450 10/30/2011 3:58pm
10/30/2011 3:58pm
probably your leak jet. Can change the size (hard work) or get a accel. pump with an adjustable leak jet. All 4-strokes that where carbed have a bog when you twist really had. I changed the leak jet on my 08 yz450 and its a lot better but still kinda there. Should have done the adjustable leak jet but didn't have the money. Either way the throttle response is a lot better.
lumpy790
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lumpy790 10/31/2011 7:16am
10/31/2011 7:16am
With the temp dropping my 450 was boging ..... opened the fuel screw 1/2 turn and it went away.

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mxtech1
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mxtech1 10/31/2011 12:10pm
10/31/2011 12:10pm
You need to drop your leak jet way down and try adjusting your acc. pump timing or wire it closed (this is what alot of the Yamaha guys do with their carbs) so it is no freeplay or delay in the fuel injection.

Most of the issue is the leak jet though. Get that down to the right size and it will eliminate your problem.
lumpy790
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lumpy790 10/31/2011 12:25pm
10/31/2011 12:25pm
mxtech1 wrote:
You need to drop your leak jet way down and try adjusting your acc. pump timing or wire it closed (this is what alot of the...
You need to drop your leak jet way down and try adjusting your acc. pump timing or wire it closed (this is what alot of the Yamaha guys do with their carbs) so it is no freeplay or delay in the fuel injection.

Most of the issue is the leak jet though. Get that down to the right size and it will eliminate your problem.
09 KXF250 is not fuel injection.... JK

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