2004 Kx 125

[kickstartkx]

I just got a pro circiut wrks pipe and vforce 3 reed the bike ran REALLY good for about 3 days now it runs and has little bit of power but i wont rev up into were it makes the power best, well i experimented and took of the reed but left the pipe and it ran alot beter but not even close to how it did whith the reeds at first.
The reeds look the same as they did new
The bike has really good compression and i did not change anything at all between the days it ran good and the days it dident
It has a 415 main jet 30 piolot jet and the needles at the 3rd pos
has this happend to any body
or can some won give me advise how to tune it or whatever it needs. Thanks

 

[MXP1MP]

I ran a #400 main 35 pilot and stock needle in the 2nd clip air screw in the 1.5 - 2 turns out range. Surprized you didn't foul it out those specs seem to rich for the main and real lean on the pilot.

 

[syko]

agreed.
seems pretty rich to me.
i run an 8 plug with a 380 main, 35 pilot, second clip on the needle and she goes.

i'm not suggesting go straight to a 380 main though, try the 400 first, that works for most o4 kx owners.