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2016 yz250x jetting thread

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I would like to start a yz250x jetting thread to help all of us out. Just list mods, elevation, and what your setup is.

I ride at 4500ft to 9000ft singletrack in idaho

Current setup

175 main,48 pilot, N3EW needle 2nd clip, air screw 1 turn out.

My bike is all stock except for a 11 oz flywheel weight and turbinecore 2 spark arrestor. Bike still seems to rich to me so I will probably be leaning it out more.

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I would like to start a yz250x jetting thread to help all of us out. Just list mods, elevation, and what your setup is.

I ride at 4500ft to 9000ft singletrack in idaho

Current setup

175 main,48 pilot, N3EW needle 2nd clip, air screw 1 turn out.

My bike is all stock except for a 11 oz flywheel weight and turbinecore 2 spark arrestor. Bike still seems to rich to me so I will probably be leaning it out more.

I dont have an x so I'm of little help but those numbers look like too much gas for that elevation.

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I dont have an x so I'm of little help but those numbers look like too much gas for that elevation.

I agree, I would think it should be closer to a 168ish main, 40-42 pilot for almost 9000ft? Maybe the x likes fatter jetting than a yz?

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No I don't think it likes more gas it's just setup for 4000ft lower than I ride. I am going to drop to a 45 pilot, 170 main, and n3cw needle on 2. Problem now is its real cold around here so riding is done for awhile.

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I would like to start a yz250x jetting thread to help all of us out. Just list mods, elevation, and what your setup is.

I ride at 4500ft to 9000ft singletrack in idaho

Current setup

175 main,48 pilot, N3EW needle 2nd clip, air screw 1 turn out.

My bike is all stock except for a 11 oz flywheel weight and turbinecore 2 spark arrestor. Bike still seems to rich to me so I will probably be leaning it out more.

FMF Q Stealth, stock pipe.  Mostly ride Single track

 

Sea Level to @ 6,000 #50 Pilot, #180 Main.  Need to put in a #48 Pilot.

#102

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FMF Q Stealth, stock pipe.  Mostly ride Single track

 

Sea Level to @ 6,000 #50 Pilot, #180 Main.  Need to put in a #48 Pilot.

#102

What needle position are you running? That setup at 6000 ft has to be real rich. How do you like the q silencer.

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What needle position are you running? That setup at 6000 ft has to be real rich. How do you like the q silencer.

It was very rich with the #50 pilot. That was the "break-in", it needs the 48 pilot, I assume the needle is in the middle, and I love the Q.

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Alt 2500ft, No Mods

 

Fuel / Oil 40:1 (Motul 800)

178MJ

48PJ

N3EW, Clip on pos 3 (Std) 

AS out 1.5 turns

 

Still need to do some tweaking as bike splutters a little just before getting onto the pipe. If i roll on throttle progressively its crisp and clean but whacking WOT especially in a higher gear it splutters before clearing around 3/4 throttle. Suspect i can go to needle clip 2 and drop MJ down?

 

Other than that really loving the bike. Lugs well, best of all is the agility. Very light and nimble.

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No I don't think it likes more gas it's just setup for 4000ft lower than I ride. I am going to drop to a 45 pilot, 170 main, and n3cw needle on 2. Problem now is its real cold around here so riding is done for awhile.

The above jetting is precisely what I have. I run Motul 800 at 32:1 and I ride sand at 4200 feet and rocky trails at 5-6000 feet. I think this jetting is perfect. When I went from 172 to 170, I felt a big jump in power. I went from 170 to 168 and the power felt less meaty and worse. I couldn't feel a big change going from 48 pj to 45, and I couldn't feel a big difference going from N3EW to N3CW either. I left it though because it feels great. I ride at lower RPMs about 25% of the time, mid about 50%, and upper about 20%. Yes, there's a missing 5%...that's when I stop and ring the sweat out of my goggles. If I have ridden in the lower RPMs for awhile without ringing it all the way out, the first time I wind it all the way to the top, it does it a little more slowly as it cleans out. It still stays smooth though. I like it. It makes me think that it's just a bit on the rich side of perfect...for what it's worth.

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Alt 2500ft, No Mods

Fuel / Oil 40:1 (Motul 800)

178MJ

48PJ

N3EW, Clip on pos 3 (Std)

AS out 1.5 turns

Still need to do some tweaking as bike splutters a little just before getting onto the pipe. If i roll on throttle progressively its crisp and clean but whacking WOT especially in a higher gear it splutters before clearing around 3/4 throttle. Suspect i can go to needle clip 2 and drop MJ down?

Other than that really loving the bike. Lugs well, best of all is the agility. Very light and nimble.

I don't think I would lean the needle to clip 2. Consider changing the power jet to a # 40

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I don't think I would lean the needle to clip 2. Consider changing the power

jet to a # 40

From what I see the 2nd clip is what they recommend for 2500ft. I think 3rd clip is to rich for your altitide. If it's cool I would run 178 main on 2nd clip and warmer 175 main on 2nd clip. 3rd clip at 2500ft is to rich in my opinion. Edited by Iluv2fly

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I don't think I would lean the needle to clip 2. Consider changing the power jet to a # 40

Thanks Kinger317, ill give that a try as its the only jet i havnt touched.

 

 

From what I see the 2nd clip is what they recommend for 2500ft. I think 3rd clip is to rich for your altitude. If it's cool I would run 178 main on 2nd clip and warmer 175 main on 2nd clip. 3rd clip at 2500ft is to rich in my opinion.

Thanks lluv2fly, i tried 2nd clip today but it felt like i lost some bottom end and still was spluttering I even tried the 1st clip just to see if it would reduce the splutter but it was still there. I then put the clip back into position 3 again. The 48PJ definitely made things a bit better but its still spluttering a little in the midrange just before the top end hit at WOT. I'm going to try grab that 40 power jet from my dealer today and will report back.

 

I even went to clip position 4 on the needle just too see what it does going the other way. It didn't clear at all. Spluttered all over with lots of spooge. 

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Thanks Kinger317, ill give that a try as its the only jet i havnt touched.

I'm going to try grab that 40 power jet from my dealer today and will back.

Grab a # 45 pilot jet while you are there. I think you might like that as well.

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Guy's, this is a good thread, but please tell us what your current riding temps are.  IMHO this is most important.

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I ride at 4500-7000 ft.  Usually 15-25 Celsius.

 

Out of the box it was so rich it was loading up and I had a really hard time getting it to clear out.

 

I'm now running:

 

PJ: 42

MJ: 168

Clip: 1

 

Can't remember where the air screw is.  It's pretty good, but if I am just cruising around and lugging, it still loads up.  If I'm on it and riding higher in the revs it's quite clean and crisp.

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3000' running 52:1 golden spectro with 48 pilot and stock main needle on clip 2. Seem pretty rich on needle but have had a warm day to mess with it. Seemed to run better at 40:1 so I may try that at sprint enduro next weekend unless anyone has found anything decent for 52:1.

Edited by nickmell

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0 to 2500' running 32:1 yamalube 2r

Been around 5-15 Celsius

Pretty new to jetting and 2 strokes, had a FI 4 stroke prior.

Was definitely rich on the pilot, fouled a plug idling on choke too long when i forgot to turn it off.

Went down to a 48 pilot and its better, might have to go down even more, AS is currently 2 1/2 out.

I went up to clip 1 on the needle (n3ew), stock was clip 2. Weird thing was i went back to clip 2 this morning to feel the difference but when i turned the gas on i was getting overflow from the carb? Is that something thats happens when the needle is too rich or did i mess something up when i put it back together?

Anyways i took it apart when back to clip 1 and its fine again.

I like it on the juice so i think the stock main is fine for now (180)

Havent done a proper plug chop but pulling it with stock jetting (was pretty black) to now its a nice dark tan color so hopefully im going in the right direction lol.

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0 to 2500' running 32:1 yamalube 2r

Been around 5-15 Celsius

Pretty new to jetting and 2 strokes, had a FI 4 stroke prior.

Was definitely rich on the pilot, fouled a plug idling on choke too long when i forgot to turn it off.

Went down to a 48 pilot and its better, might have to go down even more, AS is currently 2 1/2 out.

I went up to clip 1 on the needle (n3ew), stock was clip 2. Weird thing was i went back to clip 2 this morning to feel the difference but when i turned the gas on i was getting overflow from the carb? Is that something thats happens when the needle is too rich or did i mess something up when i put it back together?

Anyways i took it apart when back to clip 1 and its fine again.

I like it on the juice so i think the stock main is fine for now (180)

Havent done a proper plug chop but pulling it with stock jetting (was pretty black) to now its a nice dark tan color so hopefully im going in the right direction lol.

Clip 1 sounds to lean to me for your altitude. If the carb was flooding over than your floats probably stuck, not an issue with the needle.

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Clip 1 sounds to lean to me for your altitude. If the carb was flooding over than your floats probably stuck, not an issue with the needle.

Yeah i just mainly wanted to try it and see how it felt compared to clip 2, trying to learn how to feel the differences between lean and rich. It does seem to breath a little harder when i go from the throttle cracked to about 1/2 or 3/4 so Im going to go back to clip 2 next ride see if i notice much of a difference.

I thought it was probably the float but it was weird that i didnt even touch it and when i went back and switched the clip it fixed it.

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I put my twin air off my other 250 on and it seemed to lean out my x a good bit. The stock filter seems to restrict it some.

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