jetting for mountains

[glee]

I have a '96 KDX 200 w/ Pro Circuit pipe. Bought it used, so I don't know how the jetting is set. It seems to run OK in Texas. Has anyone run one in the mountains?? I am planning a trip to New Mexico or Colorado (probably elevations up to 11K feet). Am wondering what type of power loss I can expect and anything that I can do to the bike prior to leaving to optimize performance.

Does anyone know of good places to ride in New Mexico, 3-4 days in June (plenty of intermediate and expert type trails)?

 

[canyncarvr]

You don't jet a bike the way someone else does...or the way someone else DID that 'ran it in the mountains'.

Jetting is going to be a process that you do with your bike, in your area. A good place to start is to find out what's IN it in the first place.

In any case, there is no jetting recommendation that would be worth diddle without knowing the mods done to the bike. Even the method you use to oil your filter is going to make a difference....so the best person to figure it out is YOU.

Power loss at 11k feet? A LOT.

Clean your air filter. Get a new plug. Do a WOT plug chop. Check the color of the plug to determine the main jet effect. Change to suit.

Check out:
http://justkdx.dirtrider.com
<tech tips> <carb tuning> to see a chart that will give you a guide for elevation changes.

 

[Robcolo]

BIG power loss - probably 50% at 11K ! If your bike's stock, call Vickery Yamaha in Denver [service dept] & they have a jetting chart for different altitudes.

 

[RioRanchoKDX]

KDX time in New Mexico is excellent. Texas sounds like sea level. You will certainly want to go to a smaller main jet when riding at altitude (southern NM is around 4500 feet and Northern NM is around 5400 feet... both refer to the desert rides). Your '96 should be stock with a 160 main jet (I think). At a minimum, I suggest going to a 155 main jet. that's what I put in my '02. Plug foul should be reduced.
Jetting is always a mixture of art and science combined with infinite other variables...
Buenos Tardes!

 

[Bryan Kimsey]

Rio Rancho- where are you riding? I'm up near Clayton, mostly just ride on the ranch but wouldn't mind meeing up in Taos or thereabouts sometime this summer....

email: [email protected]
http://www.bryankimsey.com

 

[OKKX'er]

For what it's worth, going down 3 sizes, (from 165 to 150 ) on the main, and 2 sizes on the pilot (45 to 40) has worked for a multitude of KX's going from OK (1300 ft.) to all over colorado (9000 to 11,000 ft.) Open your air screw one turn.