I recently installed a TM36-68 Mikuni on my 2007 KLX250S using jetting I put together from the many threads about this carburetor.
Thanks to all that did the research.

Here's the data
Location; Asheville NC altitude 2300 ALT
2007 KLX250 now a 300 with KLX300 piston and barrel
Web Cams Grind 631
Uni air filter
Air box top off and backfire screen removed
FSW header pipe
KLX300 muffler with spark arrestor & open end cap
PaRay CDI unit set to 35 degree advance at 5000 RPM can be returned to 25 degrees
13 tooth counter shaft sprocket

TM36-68 current jetting
Main Jet: 130
Pilot Jet: 17.5
Pilot air jet 1.0
Needle Jet: P-4
Needle: 9EBY1-50
Needle Clip: 3rd slot from top (middle position)
Fuel/Air Screw: 2 turns out
A/P Pump Timing: Starts at 1/8 throttle and stops at 3/4 throttle
A/P Squirter: Pointed directly at the needle

The bike runs great with these settings here at home.
I'm planning a trip to Silverton Colorado and will be running at high altitudes so I'm looking for high altitude jetting settings for approximately 10,000 to 13,000 ALT so I can set the bike up before the trip.

If anyone has data for these high altitudes I'd sure appreciate it.

thanks in advance
Doug

 

I have no idea on that carb, but you will need to lean it out a bit. Maybe drop the needle on clip and downsize the pilot. It may be just fine the way it is also. I am sure you will get a better response from someone with that carb.

 

Check out the jetting spreadsheet here.

https://docs.google.com/spreadsheet/...=sharing#gid=0

This will be a good starting point for you.

 

I think yours and mine should be quite close. My '06 lives at 1700 feet. I have a 300 jug, same airbox mods, and same air filter. I have a full Muzzy exhaust. My jetting is the same as yours except I run a 127.5 main and a .9 air jet...the .09 makes it slightly richer off idle. So I'm slightly leaner on top but slightly richer than you at home. For my 2-week trip in CO last August on very high pass riding...10K-13K...I had to drop one step on the main to 125 and drop the needle from clip 3 to clip 4. The bike ran very crisply at all elevations from 6K to 13K. I wasn't any lower while in CO on my routes. When I got back home, I ran the bike around home for a few miles to see how that jetting worked at home...I had done the jetting at my first camp in CO. Oddly I didn't hear any detonation from being too lean, but the bike was flat through the mid range to top end. Went back to my home jetting and all was well. I think the KLX likes to be richer rather than leaner if you err one way or another. That's why I think yours is running a 130 main with no discernable issue. However, I'd think it might affect fuel mileage.

 

Thanks for the input
I have noticed that the bike has a little crisper acceleration when I get up to the 3000+ AVL around here, indicating that I could run a little richer on the pilot and or needle.
I think I'll try the .09 pilot air jet and see if that improves it.
Once I happy with that I'll try the leaner 127.5 main and see how that works.
BTW I'm getting 50 MPG fuel mileage with my current settings.

Great information on the high altitude settings. I'll try your settings prior to my trip.

Thanks again for the input

 

If your bike runs better the higher you go, you're probably a little lean at lower altitudes. Edit: Yes, after rereading your post, that's pretty much what you said, so disregard my observation.

 

TNC
I reread your response to my question on high altitude jetting and now have a question.
You said you installed a 125 MJ which would be leaner for high altitude and then dropped the needle clip from notch 3 to notch 4.
I'm assuming counting the notches from the top
Moving the clip down raises the needle making it richer, so here's my question
Did you mean 4th notch from the bottom thus lowering the needle making it leaner or in fact the 4th notch from the top raising the needle making it richer.
If it's 4th from the top was the needle adjustment (richer) to compensate for the leaner MJ a little.

Doug

 

Nope, you're right...I dropped the needle which leaned it out and also went to the 125 main from my normal 127.5 which leaned out the main. My normal needle position is 3rd from the top...total of 5 if I recall correctly. So I went to the 2nd position. All adjustments were leaner. In fact I did the 125 main at home and tried to run the 3rd needle clip. After a quick jetting check the first day out of Buena Vista up Mt. Princeton, it was clear I had to go to the 2nd position from the top...one step leaner on the needle. Bike ran great the rest of the trip.