jd jets



12 replies to this topic
  • ashley11

Posted May 31, 2014 - 04:37 AM

#1

I have purchased a jd jetting kit for my 99 wr 400 I live in perth Australia just wondering wot setup u guys would recomend for me ive never done this myself before so any help would be great thank you :-)

  • Fattonz

Posted May 31, 2014 - 06:14 AM

#2

I have purchased a jd jetting kit for my 99 wr 400 I live in perth Australia just wondering wot setup u guys would recomend for me ive never done this myself before so any help would be great thank you :-)



The JD kit should include all the instructions and recommendations for your conditions. I thought that was the perk of paying extra dough for the kit?

  • ashley11

Posted May 31, 2014 - 06:23 AM

#3

yeh very true mate but its always better to get a few opinions ive herd that the recommend settings that come with the kit are not always the best but for the extra you pay you would hope that there are the best

  • The Spanky

Posted May 31, 2014 - 06:31 AM

#4

The main thing you're paying for with the JD kits is their proprietary needles. Much better than OEM in my opinion.

 

Follow the instructions and try it. Jetting is based on current conditions.



  • Fattonz

Posted May 31, 2014 - 06:55 AM

#5

yeh very true mate but its always better to get a few opinions ive herd that the recommend settings that come with the kit are not always the best but for the extra you pay you would hope that there are the best


Sorry if I came across as rude. I have always reserved JD kits for my last resort attempt at attaining perfect jetting IF nothing else will work.

I am under the impression those guys run dyno's at various throttle outputs, determine where the flat (lean or rich) spots are in the power curve, then design a custom needle taper to optimize all throttle outputs......at least this is how I suspect it would be.

I would think the recommendations included within are going to get you VERY close. From there you'll just have to experiment with clip positions and AS settings, etc...

Jetting is very much a subjective and preferential matter. So it's rare that other people's preferences will even work for you given the variety of riding styles, terrain, etc... So I recommend you follow the recommendations that came with the kit, then tweak to YOUR liking. ;). Oh and please report back, I'm very curious to hear how close the instructions will get you....

Edited by Fattonz, May 31, 2014 - 06:57 AM.


  • The Spanky

Posted May 31, 2014 - 07:02 AM

#6

I have always reserved JD kits for my last resort attempt at attaining perfect jetting IF nothing else will work.

I am under the impression those guys run dyno's at various throttle outputs, determine where the flat (lean or rich) spots are in the power curve, then design a custom needle taper to optimize all throttle outputs......at least this is how I suspect it would be.

 

 

Exactly why  finally broke down and ordered one for my KX250. I didn't need the mains or pilots, but I never could find a needle for this bike that satisfied me. They were always rich in one spot or lean in another, and fixing one problem would make the other worse, etc...

 

His needles were much better than any of the OEM needles I tried.



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  • ashley11

Posted May 31, 2014 - 07:05 AM

#7

no worries mate didnt think you were being rude just saying I t how it is :-) and ive never done any jetting before but ive herd u have to play around with it abit untill you find the rite setting for your bike from what ive read on here this james dean seems to be the man when it comes ro jetting so his instructions are proberly the best way to go ;-) the kit is in the post and will be here tuesday so goin to get it done then. I will let you no how I get on..thanks for the advice :-) u wouldnt happen to know anything about the ring settings on the white bros e series exhaust would you

  • Fattonz

Posted May 31, 2014 - 07:16 AM

#8

u wouldnt happen to know anything about the ring settings on the white bros e series exhaust would you



Sorry man, I don't have a clue.....never heard of it in fact. Good luck with your jetting ;)

Edited by Fattonz, May 31, 2014 - 07:20 AM.


  • ashley11

Posted May 31, 2014 - 07:18 AM

#9

ok thanks mate

  • MANIAC998

Posted May 31, 2014 - 09:10 AM

#10

I use the JD jet kit on all of my Yamaha's, and love them! He gives you some recommendations, that will get you very, very close. Like the others have said, then you just fine tune it to how YOU like it!!!

 

Then there is another guy on here, INDY_WR450, that has a jetting chart with his recommendations, and I use his chart for when I travel to a new location, such as Baja. So that when I get there, the jetting is already dialed in, and I can just ride!!! :ride:


Edited by MANIAC998, May 31, 2014 - 09:14 AM.


  • ashley11

Posted May 31, 2014 - 10:06 AM

#11

how would I tune it to how I want it after ive installed the kit would I have to keep taking my carb off everytime?sorry ive never done any jetting before so want to learn learn as much as I can

  • MANIAC998

Posted May 31, 2014 - 10:12 AM

#12

Sadly, yes. It truly is a pain in the butt. I for one, find that the JD jetting with the Indy_WR450 chart gets me perfectly fine jetting, wherever I go. So I can just ride. Wrenching is fun, but riding is A LOT MORE FUN!!!



  • Fattonz

Posted May 31, 2014 - 10:31 AM

#13

how would I tune it to how I want it after ive installed the kit would I have to keep taking my carb off everytime?sorry ive never done any jetting before so want to learn learn as much as I can


Most of the magic lies the needle, and for that you should not have to pull the carb. I can access the needle on all my bikes without removing the carb.

As far as the jets, you definitely have to pull the carb at least once to change the pilot and possibly the main. Sometimes you can change the main just by loosening the intake boot and air boot bands, then rotating the carb to make the bottom of the bowl more accessible. From there you can sometimes remove the bowl drain plug and access the main.... With a 6mm socket...

But once you have the jets right most of your adjustments will be air screw and needle. Oh, and you would be amazed at how proficiently you can remove and install the carb when you get into the habit of doing it ;)

Yet I still long for DI :)




 
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