Jetting!!! Again and again and again!

[Friar-Tuck]

  I'm in agreement with Cam, if you can, get a 55 & 52 pilot.
     Tuck\o/

[martinfan30]

OK, thanks fellas. I will do. I'll try a 55 first and run it. I'm curious why I have the "R" needle. It's two steps leaner than the stock "M" needle... It's at the second from the top in the clip position. So I have a much leaner 1/8 to 2/3 throttle range...

I take it that the 165 main compensates for the lean needle setting...

I am getting lots of splooge coming out of the head pipe flange. Oil mix, or jetting I wonder. 32:1 Maxima Castor oil.

BTW, what series jets are the pilots?

[KXcam22]

The jets are the same as current KTM 300 jets.  Most dealers have a multi-box kit of misc jets for the Kehin.  Some of the splooge might be the 32:1.  You can make your own decision but I am not a fan of rich premixes.  I ran 60:1 in mine.  The needle acts more to the 1/4 to 3/4 range with the pilot jet overlapping the 1/4 and the main overrlapping the 3/4.  Before you go too far the first thing to verify is that the float is set correctly.  Then from there change only one thing at a time.  The 55 is a good start.  The M needle is adequate  and can be made to run nicely but it is not perfect.  I think a different needle taper is required.  JD jetting made them for awhile but they are no longer available.  YOu can be our ginea pig and we will see how well we can get your bike to run with the R.  I'll bet at your altitude it will run great. Cam.

[martinfan30]

The jets are the same as current KTM 300 jets.  Most dealers have a multi-box kit of misc jets for the Kehin.  Some of the splooge might be the 32:1.  You can make your own decision but I am not a fan of rich premixes.  I ran 60:1 in mine.  The needle acts more to the 1/4 to 3/4 range with the pilot jet overlapping the 1/4 and the main overrlapping the 3/4.  Before you go too far the first thing to verify is that the float is set correctly.  Then from there change only one thing at a time.  The 55 is a good start.  The M needle is adequate  and can be made to run nicely but it is not perfect.  I think a different needle taper is required.  JD jetting made them for awhile but they are no longer available.  YOu can be our ginea pig and we will see how well we can get your bike to run with the R.  I'll bet at your altitude it will run great. Cam.

OK, I'll try first the 55 pilot and set the float level. I will search for a thread on the float level, unless you have a thread in mind to check it.

I am also thinking of switching to 40:1 and still use Maxima Castor. Smells good, smells like victory! I'd bet, some of the lazyness, off the bottom might go away.

[Friar-Tuck]

  Float Level Adjustment :
http://justkdx.dirtrider.net/floatlevel.html

Keihin Pilot N424-21 (style) 
Note: to order a #55 would look like this: N424-21055
(series # & Jet size)
 
Fits   PWK (Kawasaki Motocross), FCR-MX (aftermarket),
 PJ,PWM (Honda Moto-X Atv), PE  20,22,26-30(Honda Moto-X, Atv)

 I like the  Maxima 927 myself, I ran that until I got a deal on the Blue Marble stuff.
  I guy at work sold his Bass Boat and gave me Three gallons.  So far so good...
(I'm not gonna open a can of worms on oil)

If you don't like the 40:1 you can always switch back.  I think you'll be fine.
  I had run 60:1 for a while with the 927 and had no problems.  But I don't spend much time over 1/2 throttle.
 Tuck\o/

[KXcam22]

Check back in this thread for an easy way to set your float level. Cam.

[martinfan30]

OK, N424-21 is the pilot series. What is the mainjet series #?

[Hillclimb#42]

 I was just recently educated on the ratio changing. I run 44:1 and have for at least 8 years, but it blew my mind to learn this: If you "lean" the ratio out like 32:1 changing to 40:1, you are actually fattening the air /fuel mixture. Lean and rich are really air to fuel terms, oil ratio is oil ratio. Less oil in the mixture= more fuel in the mixture. Am I making sense? 

[Johnniespeed]

Hillclimb#42
 I had heard that from a couple of guys, but didnt know them well enough to believe them.  I know that you have been up the hill a few times ( or is that over the hill ? LOL) and I trust your word, based on your experience.
 John 

[KXcam22]

That is true.  On some lean ratio oil bottles like amsoil it even says the words "leaner jetting may be required". It makes sense: the carb meters a given amount of fluid per air with the fluid being made up of fuel & oil.  The ratio of fluid to air is constant (stochiometric ratio of 1:14 approx).  The oil is part of the fluid but doesn't count as part of the mixture (the part that makes power) so taking away oil means that the missing part of the "fluid" is made back up by fuel. Then you have more gas in the mixture than before, making the mixture richer. Hope this makes sense. Cam.

[Johnniespeed]

KXcam22
  The more I learn, I realize how little I know.
 John

[Good]

OK, venturing into the unknown after studying this whole thread and all the articles in it over and over again, and yes, I understand changing too many things at once may not be good, but I'm going to START with almost everything changed.

My bike runs good down low, but has NO top-end power and I get killed by 250s on the pipe all the time...

I had stock jetting:

168
60
82M in middle position (3rd from short end)
7 slide
1.5 turns out
I think stock reeds, but they look like they are in great shape with minor carbon buildup here or there.  It seems like the paint has chipped off the frame a bunch.  This is the first time I've looked at them, or anything for that matter.

I am at approximately 3000' elevation with 80*+ temperatures as the norm for now, and 110*+ in the summer.
After studying the chart Paul put up, I wanted either a 162 and a 58 or a 160/55 but my local shop didn't have anything bigger than a 50 so i put that in with the 160.  I sometimes ride up to Fry Mesa at around 5,000' where the temperatures drop a little and there's a good spot to get wet for a little while before the ride home.

I do have a dented Gnarly pipe, and previous rides up to Fry Mesa have overheated bad.  The bike has never idled when warm.  It will idle for a minute or two when I first fire it up and it's cold, though.  I will START my jetting adventure with the following and tune from there:

160 main (hopefully gain pipe )
50 pilot
82M in middle position
7 slide
2 turns out

Keeping in mind that I ride on the pipe, what do you guys think of starting here?  Any and all suggestions are welcome!

Can anyone explain how to do a plug chop?  I don't follow that article well...  I don't know what it means by, "chop the throttle."  Reading the plug seems difficult also, but I'm gonna give it a shot.

[KXcam22]

 Good,
  With the stock jetting your bike must have been very rich at altiude.  I ran 55/165 at 3000-6000 and it was too rich on top at 6000' but nice at 3000'.   The needle will be the tough one since the stock N82M is barely ok dropped all the way down (clip in the highest slot).   Your temps are higher than mine so the 50, although lean, may work ok.  Make sure you watch for "lean idle runaway".  That is where temp/altitude/humidity changes to get your bike more air and the idle begins to run away by itself as the mixture gets too lean.  With the 55 I experienced that when ridiing in snow.  I would suggest eventually trying a leaner needle like the N82R.  It is a kawaski option number, although sudco might have a cross for for it.  Get the main and pilot right first. KTM dealers are good sources for jets since the 300 uses the same carb.  Also the CR500.  A Plug chop is a technique to get a clean reading of jetting on a new plug.  Essentially you ride up a mild hill (for engine load) at the throttle setting you want to check, (generally 1/4 1/2 3/4 WFO - putting tape around the grip with arrows helps) use the killbutton to stop the engine, and immediately remove the plug. Put a crap plug in and ride to the bottom. Put in another new plug and do it again etc.  Use cheap BR8ES plugs since they give the same reading as expensive ones.  Your KX will be a different machine after this, smooth and wonderful.  If you are overheating try buidling a rad overflow bottle. easy and effective. Hope this helps. Cam.

[jfabmotorsports.com]

The main jet in the Keihin FCR's on the kx450f is also the same main as the PWK. The stock kx450f comes with a 175. Also for those hard to reach places....Ebay.

http://cgi.ebay.com/ebaymotors/175-Hex-Main-Jet-Genuine-Keihin-Brand-for-FCR-and-More_W0QQcmdZViewItemQQ_trksidZp3286Q2em20Q2el1116QQhashZitem110248411478QQitemZ110248411478QQptZSnowmobileQ5fPartsQ5fAccessories

JFAB

[Good]

Thanx guys, so you think I should start with the needle in the highest, or top slot?  If I can get away from work while there's still light, I'm going to put the carb back on today and might chop a few plugs.