Help Getting Jet/Fuel/Carb - Good Plug Color

[delvect]

Got a 87 KDX200. I am having some trouble getting the fuel/carb/plug dialed in.
I have the carb jetting setup per the Fredette recommendations and the reed specs.
I can't get good plug color. The plug sometimes fouls, but mostly has hard carbon build-up and the bike/carb only seems
happy when I am above half throttle. I have gone to a hotter plug (B8ES) with some improvement. I went to the first needle clip position (Fredette specs call for position 2).
And recently went from 32:1 to 40:1. The results are not in from the fuel/oil ratio change. Will the 40:1 hurt the old gal (the bike that is).
Am I trying the right things? What's next? It seems to be OK if I ride it hard, if I play ride it fouls up pretty quick.

 

[Fred T]

Try air screw and pilot jet changes

You need to turn out your air screw a little at a time (counterclockwise) until the low end clans out. If that won't work yoiu will need to get a smaller pilot jet. try 1/8 turns at a time on air screw.

Just KDX website has carb tuning information that will hold you by the hand through it.

 

[agitt73]

THE BRAND OF 2CYCLE OIL USE CAN MAKE A DIFFERANCE
I USE GOLDEN SPECTRO AT 42/1
PLUS ON AN OLDER BIKE YOU COULD BE BURNING A LITTLE MOTOR OIL
(CLUTCH SIDE CRANK SEAL LEAKING OR THE CENTER ON THE CASE
LEAKING