jetting for 92 kdx 250 with fmf fatty, airbox mods

Aug 30, 2003
what would be a good starting point for this combo, right now it is running way rich in the midrange, after a trail ride which is short burst of W.O.T. followed by tight bends and short steep hills, I get goop spitting out of the silencer, I'm goind to tear down the carb today and check whick main, pilot and nedle are installed.
Currently the needle is in second from top clip position, can go one position leaner. Air screw is 1.5 turns out.
AIrfilter is cleaned, new plug properly gapped. Exhaust repacked, Klotz R 50 @ 40:1 as per their recomendation.
Should I change to Standard Klotz for trail riding as opposed to the R 50?
riding temp usually in the mid 20's celcius.
Thanks for any info
May 3, 2002
Get rid of the Klotz. Run a oil like the Redline or Amsoil 2000 at 50:1.

For jetting this is what I have run:

Pilot : 38
Main: 158
Needle: Stock in the 3 or 4th clip
Slide: Swap to the #6 slide (stock is 5, 6 is leaner).

That should cure most of your issues. I have a ported cylinder, hi compression, V force and Dynoport. That worked well on a 50/50 race gas mix. But presently I am running fat again with the cooler weather. So I have the next leaner pilot the R1367H to install in most likely go down to a 155 main.