KX 80 Misfiring

Joined
Aug 20, 2000
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#1
I have a 97 KX 80 that when you acellerate seems to be ok but as soon as you get to the top end of it , it starts to miss, that is the best way I can explain it. I have rejetted, changed reeds etc.....what the hell is wrong with this bike? I have gone leaner and richer with no change, reeds made no difference. PLEASE HELP>
 
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Aug 20, 2000
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#2
We also checked petcock screen, gas cap,gas line,filter, drain hoses,plug, plug wire. Could it be ignition ?
 

Chili

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Apr 9, 2002
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#3
Did this just start out of the blue? is it used and always ran that way since you got it? Since you've changed the jetting it's probably safe to assume it's not a partially clogged main jet. Ignition is certainly a possibility. We put an impact on our CDI box this year and the bike (99KX80) would start and seem to run fine until you put it under a load and then you'd swear she was about to blow up, changed the CDI and all was well again. Know anyone nearby with a similar bike that you could swap out the CDI for a test? I think 91-97 was the exact same for the KX80's.
 
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Feb 17, 2002
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#4
I wish I did know someone and I think all I need is the coil, but I don't want to buy one if that isn't it.
 
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Feb 6, 2003
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#5
Check your powervalves. My KX 125 did the same thing and it turned out the powervalve was not opening. Good luck.