JD Needle vs. YZ Needle?


9 replies to this topic
  • cac

Posted November 08, 2007 - 09:04 PM

#1

I have an 07 and I just replaced the stock needle with an 06 YZ needle (FLR?). I was amazed at the difference it made in the midrange! This thing is starting to feel like a 450! Before I cough up a few more dollars for the JD kit, can anyone tell me if it will make an improvement over my current settings.

Thanks,
Chris

Stock Main Jet (162?)
Stock Pilot (42?)
YZ Needle #4 (FLR)
2 turns out on fuel screw
Uncorked
Stock muffler
5000 feet altitude

  • 2grimjim

Posted November 08, 2007 - 09:17 PM

#2

I have tried using several jetting kits from Dynojet and Factory Pro on different bikes and have come to the conclusion that if you have the patience and spend some time to understand the Keihin numbering system and how the FCR carbs work it's not really necessary to buy a kit.

A kit may work quite well but theireis enough variety in the Kehin parts catalog that you can do without a kit.........you;ll just have to spend more time figuring things out on you own. Saving time would probably be the major advantage in using a kit.

My own preference is to use Keihin parts since I'm familiar with their numbering system (with needles anyway) and diagnosing jetting problems, and I have had hit and miss luck with non-Keihin jetting kits.

I used stock YZ jetting (I'm assuming you are working on a WR) as a baseline for my girlfriends WR in addition to disabling the Air-Cut valve and have had good results.

BTW, a 162 mj might be a little rich for 5000 ft elev. unless temps are below 40 deg.F If you are running at temps below 65F a 45 pilot might help.

Disabling the Air-Cut (only if the AIS is disabled) and using a 100 pilot air jet will help calm down low speed jetting issues at this your altitude.

  • erickdj

Posted November 09, 2007 - 08:08 AM

#3


BTW, a 162 mj might be a little rich for 5000 ft elev. unless temps are below 40 deg.F If you are running at temps below 65F a 45 pilot might help.

Disabling the Air-Cut (only if the AIS is disabled) and using a 100 pilot air jet will help calm down low speed jetting issues at this your altitude.


The 162 mj is not too big for 5000 feet altitude, in fact if his bike is uncorked it could be too small. I've used my WR with yz needle (NFPP) and a 168 mj/45 pj, runs great anywhere from 1000 to 5000 feet altitude.

  • 2grimjim

Posted November 09, 2007 - 05:21 PM

#4

The 162 mj is not too big for 5000 feet altitude, in fact if his bike is uncorked it could be too small. I've used my WR with yz needle (NFPP) and a 168 mj/45 pj, runs great anywhere from 1000 to 5000 feet altitude.


Ok. I've never jetted a bike for 5000ft and I don't know what I'm talking about.

  • cac

Posted November 10, 2007 - 05:56 PM

#5

Ok. I've never jetted a bike for 5000ft and I don't know what I'm talking about.


Appreciate the info. Can you give me a list of your current jetting settings?
It is a WR and I plan on installing an aftermarket (or YZ) exhaust soon.

Thanks!:thumbsup:

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  • rich1167

Posted November 10, 2007 - 06:28 PM

#6

Check out this thread. Theirs also a link to it in the performance index. http://www.thumperta...etting database

If you are getting good resuluts with the YZ needle. I would stick with it and not wast the $ on the JD kit.

  • erickdj

Posted November 10, 2007 - 08:44 PM

#7

Ok. I've never jetted a bike for 5000ft and I don't know what I'm talking about.


Dude, don't take it personal. I'm sure California ft are the same as Colorado ft. I was simply trying to help the guy and mentioned what jetting I'm using on my WR.

  • tmckeown

Posted November 11, 2007 - 12:35 AM

#8

I went to local dealer and got 4 different needles straight from the owners manual list. Which were then tested at the dyno with Lambda-sensor.

Timo McKeown

  • mxer1965

Posted November 11, 2007 - 10:46 PM

#9

I got my WR mid september and finally got it running perfect yesterday. I'm at 5000 ft. and put a 168 main, 50 pilot, stock 07 YZ needle, almost 2 turns out on air screw and pump linkage wire tied. It's uncorked with a WB XCR muffler and AIS gone.

This bike has absolutely no hesitation or bog any place in the throttle response. No matter how fast you twist it, it fricken rips.

Save your money and spend some one on one time with your bike. HA HA

  • JSanfilippo

Posted November 11, 2007 - 11:14 PM

#10

Ok. I've never jetted a bike for 5000ft and I don't know what I'm talking about.


Believe it or not, Erick's bike runs well at 4,000 ft with the 168 main...I can vouch for that. Grimjim, what pipe and airbox configuration are you running? Erick's bike had an open airbox and a YZ pipe when I rode it. If you're running the stock WR pipe with the stock insert in place and/or the snorkle in the airbox, a 168 would be way too fat...but then again you don't need me to tell you that :thumbsup: :ride:




 
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