JD Jetting question


10 replies to this topic
  • g123

Posted March 10, 2012 - 09:03 PM

#1

Hi

I recently installed a JD kit on my 06 WR450. I'm at sea level and ride tight woods. I fiited the the blue needle with the clip on the 2nd slot from the top and a 168 main. I put the thinner o-ring on the a/c pump. The bike runs really strongly but must be too rich because:

1/ I only need the choke on for a few seconds after starting
2/ at partial throttle the bike surges/blubber like a 2 stroke
3/ I emptied my tank in 40 miles riding yesterday (normally get at least 60 miles).

As a first step to gaining a little more economy should I go back to the origonal 165 main or drop the needle one more clip?

thanks

Mark

  • Just_a_trail_rider

Posted March 10, 2012 - 11:47 PM

#2

I would follow the jd jetting instructions.

It sounds like your fuel screw could be turned in a little bit.

surging is running too lean. Blubbering sounds like its running too rich.

Be sure to adjust the AP squirt. It needs to be right.

I did all that and then needed to adjust my leakjet. You can go from a 40-50 to lean it out when giving it throttle. That will take care of any off-idle stumble. But I ended up with an adjustable leak jet which let me dial it in perfectly.

  • miweber929

Posted March 11, 2012 - 05:48 AM

#3

Aren't those the symptoms for the throttle slide being in backwards as well? If you are going back in to the carb, do a search on here and make sure you got it in right.

You are talking almost half the fuel economy, I think it's something more than jets being off.

Mike

  • Chas_M

Posted March 11, 2012 - 07:52 AM

#4

You should consider going to the red needle as it is a little leaner during part throttle operation.

  • Stealth13

Posted March 11, 2012 - 10:33 AM

#5

Ya that's horrible I got 140km last time I filled up and use 8 liters.

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  • g123

Posted March 11, 2012 - 05:12 PM

#6

thanks for the answers guys

I'll have a fiddle with the mixture screw and then try the red needle.

The slide has never been out - but I will check when I swap needles

I've never gotten over 65 (100km) miles a tank out of this or my previous wr450

you do need to bear in mind that it took us nearly 8 hours to do the 40 miles

a little hill climb on Saturday to give you an idea..



  • Stealth13

Posted March 11, 2012 - 07:21 PM

#7

If you had your bike running for the 8 hours that is pretty good mileage then

  • Taxgod4u

Posted March 12, 2012 - 09:54 AM

#8

fwiw just jetted a new 2011 with JD kit red needle, get 37 & 38 miles per tank befor hitting reserve. Only ran two tanks threw so far but pretty consistant.

  • Stealth13

Posted March 12, 2012 - 10:50 AM

#9

fwiw just jetted a new 2011 with JD kit red needle, get 37 & 38 miles per tank befor hitting reserve. Only ran two tanks threw so far but pretty consistant.

I no longer want to jet mine if the mileage will get cut in half...

  • Krannie McKranface

Posted March 12, 2012 - 03:01 PM

#10

Red needle is better.
Adjust your fuel screw.
Un-plug the TPS
Change the apump linkage spring for better throttle response
Learn to use less throttle, now that the response is better, and your mpg will go up.
It will never be what it once was.

  • g123

Posted March 13, 2012 - 12:40 AM

#11

If you had your bike running for the 8 hours that is pretty good mileage then


The ride was nearly 8 hrs - I imagine half that time would have been spent doing this.

Posted Image

or this....

Posted Image

fwiw just jetted a new 2011 with JD kit red needle, get 37 & 38 miles per tank befor hitting reserve. Only ran two tanks threw so far but pretty consistant.


Yeah I've only put two tanks through since rejeting but both were way less than ideal.
I put a jd kit in my klr and lost about 25% of my mileage. that was a fair trade off for the performance improvement.
the near on halving of my mileage on my wr is a little hard to take - it sure does pull much better though (and run considerably cooler)


Red needle is better.
Adjust your fuel screw.
Un-plug the TPS
Change the apump linkage spring for better throttle response
Learn to use less throttle, now that the response is better, and your mpg will go up.
It will never be what it once was.


will disconnecting the tps improve mileage?

given the riding I generally do is very on-off the throttle how much impact will 'oringing' the a/c pump linkage have?

this my second wr450 and I don't recall getting this poor a mileage out of the first after I JD kitted it but I never put the oring on the pump on that one (and it always bogged like a bitch too)

thanks again for all the answers guys

Edited by g123, March 13, 2012 - 12:43 AM.





 
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