High altitude jetting recomendations?

[mntnmissle]

Hello all wise and knowing ones, I could use a little help with jetting. I'm new to the KDX, previous ride was an XR650R. I'm near Denver annd ride mostly from 5200ft to 7500ft.
'02 KDX220
FMF Torque pipe
FMF Power Core2
Boysen Reeds
Airbox lid drilled
Any suggestions?

 

[mntnmissle]

Surely someone rides at altitude, a little help please.

 

[dick]

i ride @ 4500 to 6000 ft in idaho running a fmf torque pipe and turbine core 2, carbon tech reeds, sleathy 10oz flywheel and have removed the airbox cover. the best jetting i have found is a 35 piloit, stock needle in the center slot and a 135 main. air screw is out 3/4 turns. tried a smaller main look a little white when i had a 125 main.

 

[mntnmissle]

Thanks for the help.

 

[canyncarvr]

Go here:

http://justkdx.dirtrider.net

<tech tips> <carb tuning>

Take the recommended jetting, apply the altitude chart that CDave has provided.

BTW...you list 'fmf torque' then 'fmf gnarly'. Seeing as some catalogs list the KG-30 (rev) as a TORQUE pipe for the 220....that means you have a...???? Point is a KG-35 (torque) will jet a bit leaner than a KG-30 (rev). The model# is stamped on one of the mounting flanges.

A 135 main? WhoA! The KG-35 isn't THAT much leaner!! Was that arrived at via a WOT plug chop?

Ah well..if it suits you, it tickles me;)

 

[mntnmissle]

Jetting specs didn't work at all for me. I.m going to start over at 45 pilot, needle at the 2nd clip,152 main and work from there.
Pipe is a KG-35.

 

[canyncarvr]

What does 'didn't work at all for me,' mean? WOT plug chops were way too lean (CDave's spec saying 42-142/45-clip#2)??

Considering sea level, that's pretty rich for a 220..and if you're 5200' and up, it sounds like something isn't right someplace else.

 

[mntnmissle]

What didn't work was I have been spoiled by a Quicksilver pumper carb on an XR650R and got lazy and didn't start from the begining. Checking all the settings first. The bike was setup with a 48-158 Clip@#4 Air screw 4 turns out. I ended up at 40-145 Clip @ #2 Air screw 1 1/2 turns out. Runs pretty good now. I think I'm still a little rich everywhere. Headed up to about 7500' tomorrow, probabily try 38-142.

 

[mntnmissle]

So, here's where I ended up. I took the KDX out for a little pre ride test. ;) I tried it first with the setup above 40 pilot, 145/148 main, clip @ #2 from top, stock needle air screw @ 1 1/2 turns out. Elevation 5280 - 6700 ft. When I first started the bike it seemed to clear out and run pretty well, a little hesitant on the bottom, a lttle fat in the mid range and top end. :| After a good warm up I did the throttle chop and a plug read, fat everywhere. :eek: No tan, no white just carbon. But it seemed to really clear out and run on top. I dropped the pilot to a 38 and Bang, ;) that was the deal. I adjusted the air screw to 2 1/4 turns out. Now this little green thing rocks! It hits right off the bottom, pulls clean thru the mid range into the top end without a bobble. I hope this info is helpfull someone.
FINAL SPECS: :aj:
'02 KDX 220
FMF KG 35 Pipe
FMF Turbine Core Spark Arrestor
Carbon Tech Reeds 107LT
Altitude 5280- 6500'
Pilot 38
Main 145
Needle 2nd clip from top
Airscrew 2 1/4 turns out