Coordinated Jetting changes

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bradf
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Coordinated Jetting changes

Post by bradf »

I am running a 40/152/CEK-3 and it is perfect at 35-45 degrees. When the temps go up to 60+ there is a 2% change according to the chart. So if I were to change the main to a 150, wouldn't it suggest that the needle should also be leaned somewhat like raising the clip one position. Then when the temps get to 80+ would changing to a 146/CEL be accurate? I figure that when I hit more than 2 5/8 out on the AS that the pilot will need to be leaned. I will be traveling to eastern WA to ride this year where the temps are always 20 degrees hotter and I would like to pre-tune before I get there.
'04 220 w/'01 KX250 USD forks, '02 RM125 Showa shock, Rekluse EXP 3.0, LHRB & all RB'd
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quailchaser
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Post by quailchaser »

I really envy you guys who are able to find the time to really tinker with your jetting. :partyman: I'm just happy to get out for a few hours once every two weeks. :lol:
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Post by skipro3 »

Brad,
Remember where the needle is getting it's fuel from. Changing the main jet will affect the fuel used for the needle circuit since the fuel is derived from the orifice of the main. I don't think you need to mess with the needle after you find a good one; just recalc out what main you need and change that.
At least that's all I've ever done.
Jerry

I'd rather be a smartass like carvr, than a dumbass like.... well, you fill in the blank!
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bradf
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Post by bradf »

I'll try that Ski. I'll be going over to eastern WA on the 20th and I know it will be considerably warmer and drier there. After the RB carb and head mod and running absolutely perfect jetting, I just want to stay that way. I have spent a lot of time finding the perfect jetting set-up with the 2nd SS here in 35-50 degree temps. I have yet to ride in 70+ temps and it can easily get to 90+ over there. I don't want to run fat all weekend. As it is usually very dry and fast there as opposed to the snot I get here. There a harder midrange hit is good so I won't need to drop the needle, right?
'04 220 w/'01 KX250 USD forks, '02 RM125 Showa shock, Rekluse EXP 3.0, LHRB & all RB'd
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canyncarvr
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Post by canyncarvr »

A wrong main will screw up the idle on your bike...so, what Ski said.....

If you haven't tried your CEK @ -4 just 'cuz you really like -3, give it a shot.


...oh..wait...you got the BIGbore kdx. Apples and oranges..but my 200 ran 'clean' on -3 or -4. Power delivery sure changed though!

You don't like the DEK?

Heck...you wouldn't figure I knew squat about jetting from the looks of my bike of late. I got the FRP bluuueeesssss! :shock:

I sure got a load of crap about it at yesterday's poker run... :cry:

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bradf
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Post by bradf »

I changed to a 150 and left the CEK in 3. I have noticed that as the temps get warmer I have to back the AS out for the 2nd SS. What was 2 7/16 out @ 35-40 degrees is now 2 5/8 @ 60 degrees. The most noticeable sign is that rich popping on hard decel. When I hear this I back out the AS a 1/16th or so and it goes away. Now that I have gone down to the 150 for the spring temps I suspect the 2nd SS will be at 2 7/16 again. I don't have a DEK. I have a CEL for cool weather snotty conditions.
'04 220 w/'01 KX250 USD forks, '02 RM125 Showa shock, Rekluse EXP 3.0, LHRB & all RB'd
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