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What’s the carb needle that improves an 04 RM250?

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Hey guys. I’m planning on pulling the carb and cleaning it all out etc. I feel like my jetting is good, but thought it never hurts to improve it. I’ve heard a lot of talk about certain needles that work better than stock for certain models. Is 04 one of those years? If so what’s the needle size and suggested clip setting to start?

Thanks

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That would be the NECJ on clip 3 that everyone loves. Great needle for at, or around sea level, 70F~ temps. 

Youll have to check which throttle slide is in your carb (# is on the bottom). I’ve read the 03’s had a #6. Not exactly sure what # they used in the 04’s. 05-08 I know did use the #7’s

Have a ‘06 myself. Came with a NEDH clip 4. The NECJ is just that little bit crisper during summer. I go back the the NEDH in the winter. 

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2004 should be standard with a necj

i run the NEDJ in clip 2 so it’s a bit crisper

 

Edited by kxrob
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2004 should be standard with a necj
i run the NEDJ in clip 2 so it’s a bit crisper
 

Do u have an 04? Also, what elevation are you at? I live in southwest Missouri. 1300 feet above sea level

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no , i use the needle in my kx250

i run the nedj 60-100f at sea level

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To help you get a better understanding of what all these letters mean (NECJ and the likes) the last two are the only ones that really matter. The C or D is needle length The D is 1/2 clip position richer than a C affecting primarly your 1/2 throttle position. The last letter H, W, J, K, affects your off idle throttle positions (blends pilot into clip position) with H being richer, and K leaner. 

This jetting suggestion chart may help you decide which jets works best for you. (Or at least give you a good starting point)

A419BA8C-661D-44D4-AF6E-B4C0D5F81186.thumb.jpeg.af65b020ba823fbddd602d01d807e2e3.jpeg

It typically takes a elevation change of 2000-2500’ or a temp swing of 20F in either direction to warrant a main change of one size or 1/2 clip position change, but that’s only if you’re really picky on your jetting. Keep in mind these are just suggestions, and not written in stone. Many other factors change ideal jetting. Guys that casually trail ride like leaner, and MX guys like richer. Even the fuel can change jetting. Pump gas containing Ethanol likes richer jetting do to the ethanol containing its own oxygen molecules. 

I tried the NEDJ in my ‘06 on clip 2 last summer and it was too lean,(definite loss in power), but may be perfect for you with your somewhat higher elevation and temps than I have here in Washington.

You might be in luck with your throttle slide being a #7. Completely forgot I have what I believe to be a 04 RM250 manual on my phone I downloaded off the net. (‘03 copyright date) 

https://www.manualslib.com/manual/1001171/Suzuki-Rm250.html

Check and see if this looks correct for your bike... :)

Edited by Jeremyf1
Thanks to Rob for noticing my mistake👍
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@Jeremyf1 , the D needle is actually 1/2 clip RICHER then the C needle in same clip position 

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That jet prediction sheet is awesome. Thank you

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To help you get a better understanding of what all these letters mean (NECJ and the likes) the last two are the only ones that really matter. The C or D is needle length The D is 1/2 clip position leaner than a C affecting primarly your 1/2 throttle position. The last letter H, W, J, K, affects your off idle throttle positions (blends pilot into clip position) with H being richer, and K leaner. 
This jetting suggestion chart may help you decide which jets works best for you. (Or at least give you a good starting point)
A419BA8C-661D-44D4-AF6E-B4C0D5F81186.thumb.jpeg.af65b020ba823fbddd602d01d807e2e3.jpeg
It typically takes a elevation change of 2000-2500’ or a temp swing of 20F in either direction to warrant a main change of one size or 1/2 clip position change, but that’s only if you’re really picky on your jetting. Keep in mind these are just suggestions, and not written in stone. Many other factors change ideal jetting. Guys that casually trail ride like leaner, and MX guys like richer. Even the fuel can change jetting. Pump gas containing Ethanol likes richer jetting do to the ethanol containing its own oxygen molecules. 
I tried the NEDJ in my ‘06 on clip 3 last summer and it was too lean,(definite loss in power), but may be perfect for you with your somewhat higher elevation and temps than I have here in Washington. Clip 2 with the D would definitely bog and probably seize my engine.
You might be in luck with your throttle slide being a #7. Completely forgot I have what I believe to be a 04 RM250 manual on my phone I downloaded off the net. (‘03 copyright date) 
https://www.manualslib.com/manual/1001171/Suzuki-Rm250.html
Check and see if this looks correct for your bike...

Dude. Thanks for the manual. I always wanted one. Huge help!
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40 minutes ago, kxrob said:

@Jeremyf1 , the D needle is actually 1/2 clip RICHER then the C needle in same clip position 

Oops. My bad. But yeah, that’s what I ment to say and typed the opposite. lol. :)

Must have been thinking about the 3 digit needles since I was helping a fellow out sorting out the length difference in a aftermarket PWK last night. 

Strange the length code is opposite between the 3 and 4 digit OEM needles. 

I’ll fix my mistake so not to confuse anyone...

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