Author Topic: jetting suggestions for high 20's f  (Read 1935 times)

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Offline mdw471

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jetting suggestions for high 20's f
« on: February 29, 2008, 02:18:12 AM »
Hello All

I have a chance to take my bone stock kx5 on the ice this weekend and wanted to be sure about jetting.

the temps are supposed to be between 25 and 32 farenheit.....

I am guessing that one maybe two main jets larger and richen the needle one step.

Thanks

Mark
for more information about the World's Fastest Dirt Bike, www.wolbrinkrace.blogspot.com

Offline Hillclimb#42

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Re: jetting suggestions for high 20's f
« Reply #1 on: February 29, 2008, 02:31:33 AM »
What temp was it running at last? You are right to think you will be running lean, but I think that there other things in it to consider. Where is your mixture screw? If you have it out 1 1/2 turns or more you can make the adjustment there. If you are in too far already then, you would have to fatten the jet one size, but it would have to be extreme differences to think you would need to fatten by two. How has the plug color been at current setting with warmer temps?
 I believe needle setting should stay the same, unless it hits too hard to ride. It basically controls throttle response IMO.
  I would turn the screw in one full turn and start it up and ride it at that temp to see how close you are. The safe thing to do is to refer to jetting chart and apply your temp and elevation and compare to what you have. If your k5 is bone stock, it should tell you exactly on jetting, needle and mixture screw and it will run like a new one.
  It will probably be easier to ride if you gear down some on ice and snow. Ride on the grunt power.

Offline mdw471

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Re: jetting suggestions for high 20's f
« Reply #2 on: February 29, 2008, 02:38:00 AM »
holy cow....13 minutes and a great answer :-D

Thanks for the help HC#42

Mark
for more information about the World's Fastest Dirt Bike, www.wolbrinkrace.blogspot.com

Offline kaw rider

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Re: jetting suggestions for high 20's f
« Reply #3 on: February 29, 2008, 04:04:15 AM »
i would move the needle like you said. richer setting. every 20* change i would make a change to main and needle.

Offline KXcam22

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Re: jetting suggestions for high 20's f
« Reply #4 on: February 29, 2008, 04:45:10 PM »
Keep an eye on the main jet.  Typically you will need to run at least 2 sizes larger.  Keep in mind that it is not the temp but the extra density of the air at the cold temp (more o2) that will make it run lean. Sorry that I don't have exact jetting specs.  Dezert sizing for the main might be close, high speed heavy load. Cam.

Offline mdw471

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Re: jetting suggestions for high 20's f
« Reply #5 on: March 02, 2008, 02:12:15 AM »
Thanks for all the jetting help Hillclimb#42, kaw rider, and KXcam22

plowed tt track on the ice + 2000 KX500 = YEAH! YEAH! YEAH!  :-D

Mark

p.s. two up on the main and one needle clip richer seems to work fine...no better than fine....really great   :-)
for more information about the World's Fastest Dirt Bike, www.wolbrinkrace.blogspot.com

Offline Polar-Bus

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Re: jetting suggestions for high 20's f
« Reply #6 on: March 04, 2008, 12:44:07 AM »
Thanks for all the jetting help Hillclimb#42, kaw rider, and KXcam22

plowed tt track on the ice + 2000 KX500 = YEAH! YEAH! YEAH!  :-D

Mark

p.s. two up on the main and one needle clip richer seems to work fine...no better than fine....really great   :-)


I've been running my 500 all winter out on the ice. I am running a 178 main, #50 pilot with great results. No plug fouling, and great overall running behavior I run 100% uncut CAM II fuel, so if you're running pump fuel, you might want to jat a tad richer on the main. If temps are in the low to mid 20's I place a sheet af cardboard over one rad to allow temps to properly come up. But keep in mind, now it's warming up, I anticipate leaning out my jetting in the coming weeks as temps hover around freezing and above.....I am running 14/45 gearing. Some propane heat on the cyl for stone cold starting helps out huge. Kicking over a 500 in the teens for temp is a PRICK !!!!  Heres a few pics of the "sno cone" machine: LOL



« Last Edit: March 04, 2008, 12:58:33 AM by Polar-Bus »
01' KX500
'84 GPz1100
'87 GSX-R  750
'06 HD Fatboy
'73 Kawi H1
'03 CRG KX500 Shifter kart