Jetting!!! Again and again and again!

[raredesign]

RE: KX500 2002

I was getting close to good jetting but, I just repacked my stock exhaust and now it is WAY off.
I am in Rochester NY, elevation: 558 ft.

It kind of scared me, cause I noticed that it is making a bunch of noise. I don't mean the typical surge/backfire, but i mean something more from the head. It mainly happens when it too high of a gear and sounds like a backfire, but then again, when coming off a high rev, the surge/backfire is IMMENSE! I had the air at 2 turns out, so I put it to 1.5 and that really helped. I guess the new packing caused for major airflow.
I have been running the Spectro 32:1 mix at a 50:1 ratio. what do you guys think of that? There has been some comment that as long as you get good protection, you want to run a thinner ratio, because oil burns hotter than gas. If I use more oil, will that make it run hotter and give more surge or will it settle my jetting?

I just hear all these vids on youtube, and the kx500 sounds great. Then I start mine, and if I am not on the gas full throttle, it sounds like boiling water...completely unstable. Once I jump on the gas, the thing is a smooth rocket searching for peak.

Thanks guys. I don't know how busy you guys are, but if you could leave a response, call or email that is cool. If you are willing, I will PM my info. Thanks

[KXcam22]

Rare,
  It sound like you are getting close.  Post some specific questions and I will answer.  As for the oil thing, having more oil in your mix reduces the amount of fuel per unit of air, and so leans out your jetting slightly.  Generally it is not enough that you will feel riding but only see with plug color. Cam.

[Hillclimb#42]

 I run 44:1 Super Tecniplate. I suggest any 2-stroke oil that is synthetic. Castor oils smell good, but foul too many plugs. I think the rule is the more revs you run them the less oil you need. 32:1 is good for new riders or tight trails, but i think between 40 and 50:1 is typical for a seasoned k5 rider. I absolutely stick with my mixture and adjust my carb for temps and conditions.
  My k5 runs wierd on the low end, when it is running rich. It has alot of popping in the exhaust, especially in the bottom of 1st and 2nd. I leaned it out a half turn and it seemed to come off the bottom better. If your are turned out to far on the adjustment try dropping the clip adjustment. Also at idle, my k5 has an obvious different sound than what's coming from the exhaust. Its sorta like the rumble of a steamroller, before you see it. I think that is just the coffee can sized piston doing its thing in there.
  Sometimes, when you swap pipes out, they recommend jets or silencers to go with it.

[raredesign]

Ok, here are some questions:

INFO:
I am in Rochester NY, elevation: 558 ft.
I mix at 50:1 with jetting set at 175 main/ 62 pilot
I believe the stock was 168/58.
I have not messed with the needle clip position.

The reason I jet it this way was because I ice ride, but as it started to get warmer, i noticed it ran better than before. I was still getting some surging though.
After changing the baffle packing, I got MUCH MORE surging, and had to cut the air screw 1/2 turn just to make it more manageable.

QUESTION: What do I do? LOL...no seriously, what should be main and pilot be for this elevation and mix? Should I jump to a serious 200 main or something? or just adjust the needle clip?

Thanks

[raredesign]

Ok, so i raced the clip (lower clip position) 5 rings: it was in the middle, moved to 2nd from bottom.

And....what was that supposed to do? lol

[Friar-Tuck]

Scroll down and give the this a look-see.
 http://www.teamgreennews.ca/pdf/RS03-101e.pdf
  Hope this helps
 Tuck \o/

[BigGreenMachine]

So the short version of all of this is the new 04 KX 500 jetting is the best place to start with and if you have not already done so pick up the N82M needle.

My jetting;

180 main
62 pilot
R1369N in middle clip setting

Whereas I should start with

168 main
58 pilot
N82M needle

I know there is more to jetting then simply installing these and calling it a day but that should put me a lot closer right?

[Hillclimb#42]

 BigGreen -Yep, Fixed mine. Start there, with the mixture screw out 1 1/2. Keep in mind its stock settings. You may need fatter jets for bikes that are worn, or race fuels. If you're close to stock, even with a pipe and silencer, it should still be very close. Warm it up, ride it, check plug color. Electrode should be brown.

 Raredesign - Go off of jetting chart for elevation and temperatures. I think the pilot controls idle and bottom, needle affects how it comes off the bottom to mid-range, and the main controls how it runs when you hammer it. So checking the plug after running under these conditions might give a clue to which is fat or lean.

[Friar-Tuck]

 I hope the links help.  I realize there is lots of reading and most of it reads like Greek to someone taking this on for the first time, however if you take some time it will start to make sense and you'll
have your bike runnin' like a scalded dawg 
   Hang in there guys,
  Tuck \o/
http://www.duncanracing.com/techfaq/Tech_keihin-carburetion-jetting.phtml
http://www.motorcyclecarbs.com/carbs101.pdf
http://justkdx.dirtrider.net/jetneedles.html
http://www.sudco.com/vol33/135-136.pdf
http://www.keihin-us.com/am/
http://www.cyclewerksracing.com/Carb%20Tuuning.htm
 

[martinfan30]

Hey guys, I took my carb out for the first time to check it's jetting.

Elevation 4500ft., riding in 60-80 temps
165 main
58 pilot
#7 slide
N82r needle with clip in second from top position.
105 starter(?) jet

I rode another guys KX5 and it seemed slightly more crisp. My question is, the stock needle seems to be the m needle, right?

What is the difference with needle?

[dsrtrider]

there is a good thread called "jetting again and again" that may help  http://www.kxriders.com/forums/index.php/topic,828.0.html

[Friar-Tuck]

  This might help go to    http://www.sudco.com/

Then click on the smaller catalog version (loads faster)

For v.33 Sudco Catalog please click here.
This is available divided in to small sections for dial up users.     http://www.sudco.com/onlinecat33.html
 
Then click on keihin jet needles             Jet Needles, PE, PJ, PWK, PWM  135-136

This will give you a headache if spend too much time going through the charts, but gives you a good Idea of how jet needles are measured.  I will try to find a direct cross reference from   Kawasaki OEM To Sudco..
  Please stand by... =)     http://justkdx.dirtrider.net/jetneedles.html
Tuck\o/
                                                                                        

[KXcam22]

Martin,
  The N82R is a Kawasaki option needle two steps leaner than the stock N82M.  I have seen this listed in Pro-Circuit jetting specs but I have never talked to anyone who has tried it.  I always wanted to try one but never did.  At 4500' it might be better than the stock needle(4th clip - all the way down).  The difference in crispness you are feeling is likely the pilot jet.  Your 58 may be a touch too rich.  At my 2500' I ended up running a 55. The only time the 55 felt a bit lean was riding in cold air and snow.  Pipe and reed differences can also make a huge "feel" difference.  For instance a Gnarly will make a bike feel much crisper because of the great off idle response. Hope this helps. Cam.

Ps
Danger can you move this thread into the jetting section. Thanks.

[martinfan30]

Where is the jetting forum? There is not one listed on the home page index.

I'd like to discuss this more if a mod can move this thread.

Thanks,

Rich.

[DoldGuy]

http://www.kxriders.com/forums/index.php/topic,828.0.html