Loss of midrange power

Joined
Jan 10, 2001
Messages
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#1
I have loss pretty much all my midrange power on my 98 220. It was perfect last time I rode it, and now its not. I have the same amount of power down low though, everything is alright there, but when I open it on up it sounds like there is a bunch of bananas in the pipe, it doesn't have the pinging that is usually there in my FMF pipe. I thought maybe that the reeds were finally going so I pulled them out, and they looked brand new except for a little bit of carbon which I cleaned off. So I am wondering if it is something with the carb, or jetting. Here in the south there has been this big heat wave of highs around 90. But I did not have this problem last year and I rode over 100 degrees. So I don't see what would cause the jetting to be so much more finicky. I know that temperature and humidity and all that plays a big factor in jetting, but I have never changed it because there wasn't really a need. I believe the needle jet is the big factor in midrange power, pilot for lowend, and main for topend. I have read all the jetting stuff on justKDX and feel I can tackle anything, but this one has me stumped. My fuel ratio is the same at 32:1, and all the jetting is stock, air filter is clean, new sparkplug, also when I pulled the sparkplug to look at it, it was a bit white which I know is lean, and it usually stays at a nice light tan, brownish, which is correct. I just don't see how the heat could do this just now when it has never done it before.

Thanks.

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SandRooster220

1998 Kawasaki KDX 220
FMF Powered
Renthal Supplied
 
Joined
Dec 10, 2000
Messages
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#2
I think your powervalve has stopped working. Pull the little cover off, and rev the engine to see if the arm moves. Make sure it is moving through it's full range.

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1992 KDX 250-FMF porting,two-stage power reeds, Fatty pipe, Power Core silencer,titanium rod,Wiseco Ultra-lite, Pro-Action suspension...Oh my Gawd, they killed Kenny!
 

Canadian Dave

Super Power AssClown
Joined
Apr 28, 1999
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#3
Have you recently serviced the top end? Any chance the power valves are out of time or the KIPS shaft is snapped?

Have you done a compression check?

David
 
Joined
Jan 10, 2001
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#4
I have not done any work to the top end yet. If it is the KIPS powervalve, how will I know what to do to it? Do I have to take the cylinder completely off like the manual says. Could it be carbon build up? Its just weird that one day it is fine and the next its messed up. This did happen about 2 weeks ago, but it went away after I installed a new sparkplug and rode it. I don't feel that the top end has lost its compression, but I could get ahold of a gauge and check.

Thanks.

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SandRooster220

1998 Kawasaki KDX 220
FMF Powered
Renthal Supplied

[This message has been edited by SandRooster220 (edited 04-11-2001).]
 
Joined
Dec 16, 1999
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#5
check your airfilter if you had just cleaned it and added too much oil that is exactly what would happen. If you havent cleaned it check it our for dirtyness. DO THIS FIRST!! I almost screwed up a pair of dual carbs on an xr with this problem one time.

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