11' 250 race-wa. jetting?

[adv rider]

New to forum, picking up an 11' 250 race this week. I am wondering about what jetting people are using here in Washington? I have been on a 4 stroke for last 7 yrs, happy to be back with a 2 stroke. But I am worried about the jetting, as I plan to go to desert 100 with the new bike. I am hoping to get the jetting close and usable- I don't want to foul plugs or burn up the engine. I will probably get to ride once at Walker valley before the Desert 100
I did a search, but did not find what I was hoping to find
Thanks for the info

temps can range from 30-60 degrees, and elev from 300-1800'

[Jakobi]

Confirm it has an AS2 carb, check the float heigh as per stick at top of this section. Get a Yamaha needle N3CW, and an N3EW for half clip adjustments. Start with clip in pos 3, 40/42 pilots, 178/180 main, and fine tune from there.

[adv rider]

Thanks for the info, i am going to try and get the jets today. Picking up bike tomorrow-can't wait to try it out!

OH, I almost forgot-wouldn't it definately come with the as2? I don't have the bike in view, but wanting to get the jets today.

[Jakobi]

It should, but in previous years and even at least one I know of last year, they have come with some variation due to supply issues. The AS2 has the small flat steel cap, shallow bowl, and on the cap the size will be printed. 36 or 38. The as1 has a screw on round cap and deeper bowl. They all jet differently so it pays to check. Odds are you'll have the 38mm as2 though.

Are you buying new? Theres a few things I'd do before riding the bike (like almost every other brand out)

[adv rider]

It is a new bike. I plan to go through everything, grease linkage, clean re-oil air filter, etc. I hope it turns out to be a great bike for me... I was really wanting a KTM. But I've been proven wrong before.
As soon as i pick it up in 12 hrs or so, I will see exactly what carb it has and get the appropriate jets

[Jakobi]

Hope you like it. My 2010 is basically a 2011 with the older style headlight and fender. Its been rock solid reliable.

The yamaha part code is 4SR-14916-CW-00 NEEDLE. Some sites/dealers will list this as N3CC, but as long as the part number is correct you'll get the right needle.

[desertgasser300]

Originally Posted by Jakobi

Hope you like it. My 2010 is basically a 2011 with the older style headlight and fender. Its been rock solid reliable.

The yamaha part code is 4SR-14916-CW-00 NEEDLE. Some sites/dealers will list this as N3CC, but as long as the part number is correct you'll get the right needle.

How does that needle compare to any of the jd needles for the gasser?

[Jakobi]

Somewhat similar to the JD Red. Still comparing a 2 taper (N3CW) to a 3 taper (JDs), so will never be an honest comparison.

Bit cleaner right off the bottom. People have reported the first taper as being a bit rich but that suits the engine well as its just rich enough to create good torque without breaking up. Just a matter of finding the right clip pos (which is why i suggested getting the half clip alternative too). Into the second taper it really leans out and continues to do so all the way to WOT. Result is a bottom end that will chugg up anything, a mid range that snaps like a 2T should, and a top end that keeps on pulling. In comparison I found the JD Red to be a bit bland and boring. Its middle taper keeps things richer and dulls out the transition.

JD Red: Lean -> Rich -> Lean
N3xx (yamaha/ktm) Rich -> Lean
NExx (suzi) Lean -> Rich -> Richer

[desertgasser300]

Originally Posted by Jakobi

Somewhat similar to the JD Red. Still comparing a 2 taper (N3CW) to a 3 taper (JDs), so will never be an honest comparison.

Bit cleaner right off the bottom. People have reported the first taper as being a bit rich but that suits the engine well as its just rich enough to create good torque without breaking up. Just a matter of finding the right clip pos (which is why i suggested getting the half clip alternative too). Into the second taper it really leans out and continues to do so all the way to WOT. Result is a bottom end that will chugg up anything, a mid range that snaps like a 2T should, and a top end that keeps on pulling. In comparison I found the JD Red to be a bit bland and boring. Its middle taper keeps things richer and dulls out the transition.

JD Red: Lean -> Rich -> Lean
N3xx (yamaha/ktm) Rich -> Lean
NExx (suzi) Lean -> Rich -> Richer

Im running the jd red middle clip, with 38 pilot 178 main(just changed the main to this yesterday, was a 175) I can really feel the transition to the main. Slight hesitation, but nothing extreme. Might try a 40 pilot, just nervous it might be a little to lean. My riding has become more agressive over time and with the new 12' has really made me more confident to speed things up a bit.

Ordering the yama needle, RMATV lists it as an N3CW.

[Jakobi]

You may find the JD Red works better for you. I didn't spend a lot of time testing the JD Red. I did try 40 clip 3 178 though, and immediately concluded that it wasn't interested in experimenting further with it. It still had the transition into the top end. A 2T always will, but it just felt smoother and richer than I like.

For $10 the Yamaha needle is definitely worth having a play with. You'll see what I mean once you do. Its almost light switch transition, however the nature of the GG with a 2K3 ignition means that you can easily ride around well below the hit using the torque, and when you want to party its instant power on tap.