Jetting... Needles

[GMP]

FYI to the NECJ users. Cool here yesterday AM, low to mid 40s F, so moved to the NECW # 3 and one up on the main to a 165. Bike ran perfect like thats where it wanted to be.

[ballisticexchris]

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[nevermind]

Another needle not mentioned here is the N3CH. It can be had at any Yamaha dealership. It's an optional needle for the YZ 250. I got sick of jetting and needle changes and this needle is the hot ticket. This needle works from sea level to nosebleed elevations. I use premix amount, fuel, and airscrew to adjust my jetting. More oil 40:1 (leaner) and U4.4 or Street blaze for mountains. Less oil (richer) 60:1 and Street Blaze for lower elevations and desert.

As with any needle adjustment start off rich and lower needle as needed. Try the N3CH. It might surprise you how versatile it is. I have not touched my jetting in over 5 years.

Are you using that on a 300RR or ?

[GMP]

That's a popular needle for a 250, but can give a 300 more hit all else being equal. For eastern woods not usually the preferred result. The NExx series is a better choice as its straight section is longer therefore smoother off idle. BTW if you do the math 40:1 to 60:1 is insignificant. Switching fuels much more so.

[ballisticexchris]

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[GMP]

The desert is a different planet than the east. I was in San Diego this summer on vacation, no riding but I did hike a bit and traction is like Velcro on desert rocks. When greasy roots, rocks, green mossy logs in tight trees are on the menu you don't want a 300 with hit. Even for racing, it's a needless energy waster.

[Leon_RR250]

Hi!

Can somebody explain to me what difference I would feel by going to a NECW needle from the stock N2ZW on an oil injected 2016 RR300? Temps have been in the range +2 -- +14 C, 42 pilot and 175 main and stock needle setting, adjusting a bit only the air screw. Power is really great and linear through the mid towards the upper revs (nothing like the MX type hit of the 2013 RR250) but still I have not taken it to the rev limiter (7.5 hrs now). Consumption is about 4 litres for 28 kms. Also, would the stock needle raised to 3rd position would be better than NECW in 3rd position for temps from -2 to -10 C?

Leon

[GMP]

I think its a bit smoother off the bottom and perhaps revs out a little better, this is on a '13 and '14 300. Start with one main leaner and one pilot richer using the NECx than you would with the N2Zx. Sometimes same pilot is fine with the air screw in a bit more.

[Leon_RR250]

Thank you Glenn!

Adjusting range for the air screw has been 2 and 1/2 to 2 and 1/4 turns, so it may be a pilot change is not needed. Now only to decide to go to a Suzuki dealer to order it...

Leon

[Trailcutter]

Thats exactly right, you can't apply the Keihin codes to OEM special needles. The range of Suzuki needles can be found in the RM250 parts list. In short, there are two lengths, third letter designating either a C or D, with C being a half clip position leaner. Starting diameters range from F(richest) to K(leanest), but all but the W and J can be pretty hard to find. Good news is you won't need them.

Same thing applies to the stock series of needles. The NECJ cleans things up but also smooths the bike out even more off the bottom. I personally think it makes the 300 more ridable in the tight, and you can be more aggressive without the bike biting you.

I'm trying to decide what Suzuki needle will best fit my current jetting. I noticed the beta chart uses similar first and last letters as a Suzuki chart when naming the needles. On both charts needles start with "N" and end with ether "J" or "W" (at least for the two needles I'm most interested in). Does the "J" and "W" from both the Suzuki and Beta charts correspond to the same spot and shape for each needle? Example, does the "J" on the Suzuki chart mean the same as the "J" on the Beta chart? If so, how do the two middle letters corespond chart to chart? Does the third letter on the Beta chart also correspond to length of the needle by half step? My jetting is working well from the Beta chart but want to smooth things out by switching to the Suzuki needles and want to make sure I'm understanding enough to choose the correct Suzuki needles.