Proper Jetting

[KTM-Lunatic]

I need some help on the proper jetting on my sons 99 200 exc. Im down here in Ms running the SERA enduro races. This last race he ran out of gas at about 36 miles and fouled a plug when he put the tank on reserve and when he ran dry.

 

[Buckholz]

1) Check float height, you can get away with a coupla mm lower fuel level, will help with peeing out less fuel in the overflows, leading to better mpg.

2) We mostly trust the jetting called out in the Orange KTM book, look in the back. Jet all four things for the proper elevation and temperature. Four things are slow jet, airscrew, needle and main.

 

[D Lafleur]

KTM Lunatic, You will need to pull your carb for this, so while you are at it, go ahead and check your float setting. Email me your slide, needle, and jet sizes at [email protected] . I also need to know if you have any bogging or leaning problems. I assume if you are using the stock needles, you will. Just send me a description of what the bike is doing. Just for the record, I threw the KTM jetting spec.s away. They dont work in "Eastern style Enduros". They probably work just fine in open/ non humid riding.

 

[DJMcRage]

I just today picked up my repaired pipe for my 01 300 EXC. I also recently took the carb apart and made the following adjustments:

a 172 main, ;NOZI, Third notch from the top, 42 pilot jet. The slide is a 6.5 Kehin. Most of my riding is singletrack at about 960' ASL

 

[DJMcRage]

I just today picked up my repaired pipe for my 01 300 EXC. I also recently took the carb apart and made the following adjustments:

a 172 main, ;NOZI, Third notch from the top, 42 pilot jet. The slide is a 6.5 Kehin. Most of my riding is singletrack at about 960' ASL

 

[DJMcRage]

I just today picked up my repaired pipe for my 01 300 EXC. I have done my annual maintenance and am ready to test out my first jetting project. I read all the information I could find, took the carb apart and made the following adjustments:

a 172 main, ;NOZI, Third notch from the top, 42 pilot jet. The slide is a 6.5 Kehin. Most of my riding is singletrack at about 960' ASL

The bike is great in most upper Michigan riding circumstances, but when it gets snotty, it becomes a handful ... I have Bridgestone tires made for those conditions, and I changed the pilot from 45 down to 42. primarily because the air screw was out so far, and it still gurgled pretty good at the slower speeds. I hope this pilot jet change will do it, but if you guys(gals) can think of anything I missed, I'd appreciate it if you let me know.

DJ
01 300 EXC

 

[D Lafleur]

DJ, I dont particularly like the "NOZ" needles, but based on location and your jetting you should be ok. If you load the motor between 1/8 to 1/2 throttle in gnarly terrain, you will most likely foul plugs.

 

[DJMcRage]

D LaFleur

Thanks for the feedback ... I imagine there is something about the taper, etc. that you don't like about the NOZ needle, and all I know is that the former owner changed the stock needle to the NOZI.

Can you tell me, based on the settings, riding area and elevations I provided, which needle I should use?

Also, I'm trying to understand your comment about fouling plugs. Is it based on your experience with the NOZ needle? So far, there I have had no problems with fouled plugs, however the last plug I removed did look darker than the ideal, and there was spooge coming out of the end of the silence before I repacked it. Does that tell you anything? I had already concluded that the bike was running rich, but that's about it ...

Any advice will be appreciate

DJ

 

[Layton]

The NOZ* needles run rich around 1/8 to 1/4 throttle. Unless you are real agressive that's probably about where your throttle position is on single track.

A straight taper needle like a DDJ or DDK would probably work much better. If you go to one of those also go up several sizes on your main jet. The needle is slightly larger so it usually needs the increase in main size to keep from running lean on top end.

 

[D Lafleur]

Layton, you got it. The NOZ* needle's first taper is very aggresive (RICH). At 960' ASL, with the warmer weather coming you are close to the right settings. I would raise the clip one position to #2 spot. Just check the plug after a little riding and make sure you are not too lean.

I had the NOZI needle running 42/72 6.5 slide and 1.25 turns out at 100' ASL the bike ran too lean at the top and too rich in the gnarly stuff. Go figure, It is that first taper, it is just too aggressive. With your altitude you will probably do fine. The type of stuff that gets us is the single track where "BarkBusters" got their name.

I hope this helps.

D.

 

[DJMcRage]

"The type of stuff that gets us is the single track where "BarkBusters" got their name"


Oh to have that problem ... tight single track is getting increasingly harder to find here in MI

Once again, thanks. I've copied your notes, and will try them to the letter. What was once a very intimidating subject is now sounding more and more familiar. If these adjustments work, I'll have to buy a bigger helmet.

 

[miwebb]

I am the proud owner of a 99 200 mxc and suggest you go with the DDK needle. You may have to change your main jet and your pilot jet, but it will really clean up the bottom end and make the bike run better down low. If you change reeds, do not go with Boyesen Pro Series reeds. They make the bike bog and run poorly.

 

[D Lafleur]

Miwebb, you are correct a DDK needle will clean up the stock act, however if someone changes to this they need to run a much larger main jet.

See you on the trail.

D.

 

[fishhead]

ddj-3 and ddk-3 are good places to start dcj, dck in clip positions 2 and 3 will be 1/2 clip position leaner and richer respectivly than the dd_ counterpart. cek and cej are richer than the dd_ needles up to 1/4 throttle and leaner above. The ce_-4 will closely match the noz_ -2 through the 3/8 to 3/4 throttle opening but will be much cleaner below 3/8 throttle and leaner at 3/4 and up.

Invest in a copy of the JD.Jetting spread sheet and you will be able to duplicate your setting for any conditions you will encounter. It will help immensly to take good notes of the temp altitude conditions etc. to zero in on your best jetting package. Rider feel is the most important parameter, provided you don't cook the piston.

In my 250 I found the ce_ -4 to be a little flat and zappy in the mid section until temps got up above 75 or so. The dd_ and dc_ needles are much better for cooler temps.

Have fun :)