2003 KDX200 Top end power woes

Joined
Jun 8, 2008
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#1
Hi guys...
This is my first post on this site so go easy on me. :)
I have just bought an 03 KDX200 and I am wondering how to give this thing more top end power. It has an FMF gnarly woods pipe with a powercore 2 silencer. The main jet is 152 and the pilot jet is 42 (keihin PWK35). The gearing is 14/48. Now heres my problem, this thing pulls like a train in the low to mid range but power drops off pretty sharply in the top end. I have heard that a v-force 2/3 reed kit could give me more top end but I dont want to sacrifice the low/mid power too much. Is there a way to have my cake and eat it too?? Any suggestions about any other mods would be greatly appreciated as I would like to have a nice top end with the low/mid power that I already have. Feel free to tell me I am dreaming and it is not possible to have it all. (or maybe it is..)
Thanks in advance........
 
Joined
Apr 15, 2002
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#2
First observation is that you are geared taller than stock and you are bogging the engine (by load) on the top end. For about $12 you can change to a 13 tooth front sproket (which is stock) and see where you are. I think you will be surprised by the results. Remember this is a 200 cc bike not a 250 up. It has to wind up pretty good to put out much power. Remember the KDX is basically a trail bike and not a motocrosser. Cheers John
 

Mac

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May 17, 2000
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#3
That torque pipe is limiting your top end, try a rev pipe you will see a huge difference. Yes, you will loose bottom end but life is full of trade-offs.

If you decide to stay with the torque pipe you could retard the timing a few deg to see if that helps. Jetting can also affect how the bike revs, too big on the main jet can limit RPM but check your plug before going too much smaller than a 152.

The v-force is a nice product but it's not going to give you a noticable improvement in top end like a rev pipe will. JMO