Jet Kit

[TN94z]

Should I buy individual jets or a jet kit? If a jet kit, what kind and where is the cheapest place? Also, from what I have read, I think what I am reading is that the NCVQ(I think I have that right..but you know what I am talking about though) needle is the same as the yz450f dirtbike needle right? Does this needle come with a jet kit? I noticed that in the JD jet kit, it has a high altitude and low altitude needle, is this anywhere near the same as the NCVQ needle? Thanks in advance

[sMoKiNyFz]

Buy the kit. I'll get back to you cause my dad bought that for his so i'll ask him.

[jr1975atv]

Buy your jets individually it's alot cheaper and you still have to figure out what works best anyway

[4TraxRider]

If your totally in the dark, get a jet kit, they come with some instruction on where to start. if you know what your doing and what you want to do, then just get individuals, it's a ton cheaper.

[Kennethyfz450]

I hook you up with the best information i can find..

[Kennethyfz450]

BASIC JETTING

WHEN TO USE THIS......pilot..NEEDLE..CLIP...MAINJET..AIRSCREW


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summer STOCK...........45....stock....#4....160......1.5 turns out try different settings


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WINTER STOCK...........45....stock....#5....162......1.5 turns, try different settings


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sumr airlidoff baf out..45...stock....#5....168......1.5 turns, try different settings


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CAM MOD SUMMER PIPE K&N 48....NCVQ....#3....170......1.5 turns, try different settings


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cammod winterpipeK&N 48....NCVQ....#4....172......1.5 turns, try different settings


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cammod,port,K&N pipe 48....NCVQ....#4....178......1.5 turns, try other settings


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cammod, bigbore K&N Carb bore, Dynatek 52....NCVP...#4.....200......1.5 turns out


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Dogrider 508, Bored carb Ported head, Ported carb cams, PIPE, 63...NCVN....#2.....215......2 turns out summer 80 degrees. runs perfect.

[Kennethyfz450]

Ok, HERE IS JETTING IN A NUTSHELL:
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You motor carburetor needs air and fuel.Your carb is designed to make it mix correctly for any engine speed, So much air to so much fuel. This is not rocket science. I wont even tell you the ratio cause to you it doesnt matter. When the air flows fast, a venturi vacum makes a slight pull, and the gas comes up from the float bowl and evaporates into the moving air. T


when at a certain RPM the airflow sucks up just the right amount of fuel for a certain throttle setting, the mixture is just right. But when you add on an airfilter, lets say, then the pressure difference changes (easier airflow, less vacuum effect) and not as muc fuel gets sucked up and the fuel air mixture is lean. so you have to rejet, make the jet holes a little bigger, and then that decreased vacuum combined with a bigger hole makes the same correct jet air/fuel mixture.
So when you add a pipe (MORE AIRFLOW) it throws off the perfect air/fuel mixture and you have to readjust, until it is just right.

another point, right from STOCK you are already too lean, so you should jet right off the bat anyway. a perfectly stock setup should have a 45 pilot (stock is 42) and a 168 mainjet right off the bat. that works pretty nice so you can take the baffle out and remove the air filter if you want also without any danger.

RICH means a little more gas in the air/fuel mixture or a litttle less air, like you go up to pikes peak with your quad you will be too RICH. NOT DANGEROUS.coming out of the carb.

running rich feels like it is RUNNING and gurgling and sometimes black smoke out the back and you just dont have power.

running lean you can tell it pops and backfires a lot and runs REALLY HOT the pipe just SCALDS you, this is not so good for your motor. (

The 450 runs hot enough to see a pipe glow at night, that is normal, but when you are lean it glows BRIGHT CHERRY READ and in the daytime you can see it and it melts riding pants, this is probably too lean. go up on the jets.

LEAN means not enough FUEL in the mixture and also can be thought of as having a little more AIR than you would like to have in the mixture, like if you were jetted in DENVER and then went to GLAMIS that would be lean orthat would be bad. You would be LEAN since the increased air pressure compresses more air through the carb, more than expected, raises the air/fuel ratio. LEAN IS HARD ON THE MOTOR. (and that means more gas/air ratio)

Running lean is hard on the motor, there is too much hot oxygen in the motor that didnt get burned up, and 1200 degrree oxygen MELTS ALUMINUM PISTONS over time. like a cutting torch. Make sure when you jet make sure all the hot air is used up by putting enough fuelo in there by making the jets bigger. when you go up a mountain the air gets thinner and the carb becomes a little rich, so sometimes you have to make it a bit leaner. that is usually just moving the clip on the needle down one clip, (like from clip #5 to clip #4) or more towards the FAT end and away from the skinny end. that usually solves the problem.

when you ride around in Denver, and are jetted fine, then you go to Oregon or Glamis you will need to make it richer. usually one more pilot up and a needle clip up higher like from #4 to #5 on the jet needle (see videos below).

when the summer gets HOT the air gets thin and the fuel stays the same, and so you end up richer in the summer, so you have to go down a needle clip in summer and up a needle clip in the winter when it is cold out.

In temps below 32 you have to go to a pilot 48 and two needle clips up and main to 168-170 with a basic quad with aftermarket pipe and K&N aftermarket airfilter. for example.

Jet kits contain a needle and some pilots and some mainjets that you buy for a set price. these are better than stock, but they were not taking into account all the mods most people do to these quads. so they are insufficient if youdo all the free mods

for example, a cam mod change (rotating the exhaust cam one tooth clockwise) gives more upper end power for drags, and n air filter and pipe and like cams you will need a mianjet in the 170 -175 range which doesnt come with the jet kits usually.

When adjusting your jets they will range from pilot 45 to 48 SOMETIMES 50 or 52 if you do engine work. theneedle is from the gytr jet kit, a YZ-450 dirtbike needle called the NCVQ needle and you will run clip #3 or #4 (#5 if you have engine work())

mains will be from 168 to 170 to 175 in general. with bigbore engines, you will have pilots as high as pilot 62 and main needle clip #2 on NCVN (#6 on NCVP) needle and mainjet of 215. but this is extreme, and if you try these jets on a stock quad it wont run right at all.

so you have to know your mods, and then adjust the jets. Each time. Just changing the mainjet may work a little but it will not run good. the pilot the needle and the main all have to be changed each time if you want perfect jetting. in general. (see videos below) so, jet EVERYWHERE, not just main jets. One person wrote to us and said he didnt feel comfortable changing the needle clip , could he just increase the main jet. We said Yes, but you only get halfway there and it wont run real good, just pretty good. So we made the videos for him. He was happy. Now he can .

[Kennethyfz450]

HOW does a carburetor work?



Making a perfect airfuel mix is easy if the engine runs wide open, or runs at a certain throttle. But airflow is not linear, that means it changes differently at diferent speeds. Jetting is very easy if you have one set speed right? But if you are to go a little faster, and now the air moves faster, and to get to that ratio you need a bit more gas, just a bit, not to much and not too little, the jet hole allowing fuel to come in has to get larger. that is what the needle jet does, as the carb opens up the needle slides out and it gets skinnier and then the gasoline opening lets in more fuel. The needle clips on the needle make it THINK it is opening a bit more or less from stock, if you change the needle clips..
Now for the low end.

Airflow is not linear, it soes not venturi (suck) too well at low speeds so they designed the little bit of air to go through a smaller hole when idling and added a little idle jet the idle jet lets more fuel in and is the ONLY jet that works at idle, along with the choke jet circuit. So IDLE adjusts the low end and low throttle zone.



a jet is just a little hole that gas flows out of into the JETSTREAM of air sucking through the carb. at WIDE OPEN thottle the needle is pulled all the way out so the limitation is just at the top end, or the main jet.


the mainjet affects the mixture mostly from mid to top end. but in real lie that is the case, the mainjet is like the PIPE the MAIN IPE that supplies water to your house, it sets the upper limit when the needle is pulled all the way out. And because of the way flow dynamics works, it adjusts mow much the needle works at upper end also a bit. so think of the mainjet as top 1/3 to WOT jetting. The mainjet should alway be adjusted last on the 450. this is bqckwards from non fcr carbs, but jetting is easier if you set the pilot first, needle second and mainjet last.)


the pilot hole ALWAYS PUTS OUT GAS all the time from low to TOP END the needle opens the hole more and more until top end all that the mainjet does is limit the top end flow.


all the jets add together.


the first hing on jetting is to put the jets back to stock, and add all your add ons, pipes airfilters, cam mod whatever and try and start it. as you add modes your jet size will increas up to 20 percent more NEVER NEVER LESS THAN STOCK makes sense? do your PILOT FIRST! since it will have an effect later on everything, and the needle makes no effect on idle nor does the main. if it does not start, go up on the pilot. leave the choke OFF and leave the airscrew at 1.5 turns at all times.


go up until the pilot lets it start. if it idles ho, go UP on the pilot! go up on the pilot till it idles smooth.


starts on first kick and idles smooth.


NOW LEAVE THE PILOT ALONE!


now run it half throttle. I bet it pops and cackles a bit, go up on the needle.


look at the video. stock needle now comes on clip #4


IT USED TO COME ON CLIP #3 AND DUE TO THE COMPLAINTS FROM OUR WEB SITE AND OTHERS THEY CHANGED IT. WHEN WE GOT QUAD #200 IT WAS ON NEEDLE THREE!)


OK A STOCK NEEDLE IS GOOD ONLY FOR A [PIPE AND AIR FILTER


THAT IS IT. IT CANT HANDLE MORE THAN THAT.


if you make your main GO UP THAT WILL INCREASE YOU NEEDLE A BIT ALSO! BE AWARE


ANY MODS AT ALL YOU WILL NEED AT LEAST A 165-168 MAINJET WITH THE STOCK NEEDLE.


HERE IS WHERE IT SEEMS TO GET A BIT TRICKY.


THINK OF THE MAINJET AS THE DIAMETER OF THE PIPE TO YOUR KITCHEN SINK, AND THE NEEDLE IS THE FAUCET.


you can buy bigger faucets BUT THEY WILL BE LIMITED TO YOUR pipe right?


iF YOU PUT A LEARGE NEEDLE ON THEIR (A firehose ON YOUR KITCHEN SINK IT WONT WORK, THE PIPE IS TOO SMALL.


IF YOU PUT A KITCHEN faucet on a fire hydrant it will put out more water but it wont be right, too much pressure!


YOU have to match the pipe with the faucet!


90 percent of you guys will be here at the NCVQ needle and mainjet around 168 and needle clip #4 or #4 or #5 needle NCVQ (yamaha dirtbike YZ-450 is the next size up, with that needle you shouold be running a 168-170 mainjet


For ported motors, BIG AIRFILTERS VALVES CAMS CAM MODS PORTS you may need to hit an ncvp if that is not enough you need a NCVP needle but your mainjet is 175-180


if that is not enough you need an NCVN with mainjet around 210. this is for bigbore motors and strokers and bigger bored carbs otherwise do not try it.


Ok look at a needle it has 7 slots. the slot nearest the fat end is slot 1 the one closest to the skinny tip is slot #7


lets say yo had a needle with 12 slots, you would never need another needle at all! you could have one dneedle for everything?


if you need richer you would just move the needle clip down one more and up the mainjet whenever.


BUT WE DONT HAVE NEEDLES WITH 12 SLOTS!


why? they would be too long.


look at the needle, the more it pulls up the skinnier it gets thus making the hole bigger to let more gas out right? so moving the clip down lets in more and more gas! easy.


to go richer, lift it up more!


ok a stock needle you can go from clip #4 to clip #5 6 doesnt work without grinding the needle.


SO buy a NCVQ (jetkit needle) and it is thinner narrower.


a stock needle on clip 5 is like NCVQ on clip 3


A NCVQ on 5 is like NCVP on 3


a NCVP on 5 is like NCVN on 3 get it?


If you buy the next size needle you move the clip down 2 for the same effect !


NOTICE THE LETTERS GO UP as you get RICHER?


WHY?


so only secret jetters can figure this all out.


stock is leaner than NCVQ which is leaner than NCVP which is leaner than NCVN which is leaner than NCVM.


THERE IS NO NCVO neelde! WHY? for more confusion.


YOU WILL BE AT NCEQ or NCVP 95 ppercent of the time.


NCVQ on clip 5 is like NCVP on clip 3 and like NCVN on clip 1


this is not hard, it is just MADE TO LOOK HARD BOTOOM LINE.


So far what we have told you cost us easily 2000 dollars to figure out.


and I think it is about time to spill the beans.


Now about now, you will hear about how we work out of a garage, so everything we have said must be wrong. you try it, then you listen.


PLEASE COPY this info and keep it, as this site is going down soon, The negative PR is much greater than the free info in this site.


soon all the others who dont like this information can get back to selling jet kits and engine summer coolant.


so what do you ACTUYALLY DO? RUN YOURS STOCK with a 45 pilot and a 168 main jet and needle clip #4 and take your baffle out and airbox off and drill your pipe. Now go race 90 percent of the 450's and win.


If you want more mods like a after market pipe or K&N, then


ok, this is how it goes, GET and NCVQ needle, or an NCVP needle.


if you are going to mod mildly Pipe, airfilter, cam mod, NCVQ is fine for you around clip 3 or 4


if you are going to rip, and do camse and bores, you will need to go NCVP or even NCVN.


otherwise, pipe and airfilter basic,


pilot 48 NCVQ #3 main 168 and adjust up and down a little to even a 175 maybe


(NCVQ on #3 would be NCVP on #1. Don't get an NCVP needle unless you are planning on big bores and stuff like that.

[Kennethyfz450]

SCENARIO:
Ok lets say you are at glamis pilot 48 NCVQ #4 and main 174, you have a lot of mods, the sun is out and its about 70 degrees with a breeze and you don't want to jet, you want to ride. So you do, cause you listened to us and set it up right rather than jetting around all day. LOL.


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SCENARIO 2:
you go to St Anthony 4000 feet you just returned from Glamis, and you will be pilot 48 CLip #3 main 170 or even pilot 45 if it idles too rich. And cause you listened to us rather than experimented, you find you ride pretty good. LOL. But you just were beat or you don't FEEL the power very well. well, then adjust the airscrew! 1/2 a turn at a time, careful not to go over 3.5 turns out or it may fall out and you loose your little o ring, and then the ride is over and you all go home. try a jet higher and lower like minjet 172 or 174 . you can also try a needle clip down and check it out, but if you get hot, put it back. now when you drive it if it has a WEAK spot, that is and area to richen up. always fine tune with main jet go up one or two till it runs worse then back down. THEN FINALLY ADJUST THE AIRSCREW a quarter to a half a turn either way NEVER ADJUST THE AIRSCREW TILL YOU ARE PERFECT JETTTED at least as good as you can get. Always adjust the airscrew LAST. or you will be playing jetting blues games for days.



REMEMBER AIRSCREW MUST STAY AT always 1.5 till ready and jetted, then fine tune it..


read on for more details.


NOTE all jetting above is for GYTR NEEDLES if you have a JD jet kit the principles are the same except you will be one pilot lower like a 45 instead of a 48 and the main will be one or two lower (They make a richer needle and they dont tell you.


this cause confusion when talking between the too, and then riders always claim YOUR JETTING TOO RICH JUST BUY ONE OF THESE KITS AND YOU CAN RUN LIKE ME!


dont listen to thatn stufff. jet richer till you beat them


we have beat many many jet kit 450's in fact no jet kit 450 ever beat us yet.


you can do this easily with the above guidleines.


THE BEST WAY is to talk to quads WITH YOUR MODS and assk their jetting, and maybe they are nice enought to share lieke we did.


if you have a few mods and have to start somewhere, start at


pilot 48


NCVQ#3 and mainjet 168


try that then go up a little and down a little from that.


This is IT! dont listen to the tall tales. if you hear us badmouthing us, just smile. we dont sell anything.Ask yourself WHAT MOTIVE do they have? and if MY quad runs better, why are THEY ANGRY ABOUT IIT>? LOL. here, watch these videos.:
JETTING VIDEO: REMOVING THE CARBURETOR WITHOUT BREAKING ANYTHING

JETTING VIDEO: JETTING THE NEEDLE CHANGING THE NEEDLE CLIPS WITHOUT BREAKING ANYTHING

JETTING VIDEO: JETTING THE MAINJET AND PILOT JETS WITHOUT BREAKING ANYTHING

JETTING VIDEO: PUTTING BACK THE CARB WITHOUT BREAKING ANYTHING



JETTING VIDEO: JETTING THE FAST DOG WAY



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DOES YOUR 450 RUN ROUGH AT IDLE? (LEAN PILOT) Go from 45 to 48 and drop needle one clip

Does it not even idle unless you hold the throttle down? (LEAN PILOT)

Idle screw just won't get it idling fast enough? (LEAN PILOT)

Won't even start after the cam mod? (LEAN PILOT)

DOES IT (pop) ON RELEASE? (LEAN NEEDLE)

DOES IT HESITATE ON ACCELERATION? LEAN NEEDLE)

DOES IT GET VERY HOT ON IDLE? (LEAN PILOT)

DOES IT GET HOT RUNNING? (LEAN SOMEWHERE)

DOES IT HESITATED AND POP AT WIDE OPEN THROTTLE? (LEAN OR RICH AT WIDE OPEN THROTTLE)

Then you need to learn about jetting.

Please read the following after watching these videos. (Jetting is not that scary.) A YFZ owner must learn these things.

[Kennethyfz450]

http://www.eskimo.com/~daddog/index.htm

that would have been a whole lot easier :D

these people are good , and very honest..

they also have video's u can watch.

[airheadedduner]

Originally posted by Kennethyfz450


Don't get an NCVP needle unless you are planning on big bores and stuff like that.

At the shop I work at we have been using the VP needle in all the yfz's we have done with no problems at all.

YFZ with slip on and K&N

1 1/2 turn fuel screw, 45 pj, VP needle 3rd clip, 168-170 main.

yfz with full pipe and K&N

1 1/2 fuel screw, 45 pj, vp needle 3rd clip, and 175-180 main.

This is all for 0-1500ft elevation. They have all run great with no complaints. THe cam mod has not been effecting jetting as far as I have seen.

[Kennethyfz450]

yeah my shop also uses jet kits and je pistons and weisco..

it doesn't mean they are the best, just means its common for customers to buy that part.

[airheadedduner]

Your not reading my post. WE are recomending and installing the VP needle. We get lots of customers that come in and buy a YFZ and a pipe and want us to install and jet it. I don't know about you but we jet it right, not just install what the customer thinks it should run. I don't even initilly tell the customer, "hey, these are the jets I am putting in your bike." I do the job right and then write it out for them. We stock all the proper jets and needles so customers are not wasteing money on what ever god awful amount a jet kit cost. The vp needle works for a wide range of aplications. I beilive it is one of the needles yahama uses in the GYTR jet kit. I was refering to your coment about the VP needle only being good for bigbores.

[Z-135]

I have a CHM slip on pipe, pro design K&N air filter no lid. I have a dyno Jet kit. The kit said to run a 48 pilot jet 160 main jet needle on the 5th from top spot 1.5 turns on the air screw. It ran like crap! So I put a 150 main in and it was a lot better. But now if you hold it 1/4 throttle (when riding) it will cut out. Any help? Would that be the pilot jet? The dyno jet are a different size! Thanks!

[Quad18star]

Alright so I'm getting a Full Sparks for my YFZ with their Jet kit which I think has the NCVQ needle . I'm at about 1000 feet elevation with average temps during the summer ( about 70 degrees) .

Now just to get this straight ... when looking at a needle , do you count the positions from the bottom or the top . Example on a needle with 5 settings ... would position #3 be 3 spots from the top or start from the bottom of the needle and count upwards?

I'll have the Sparks pipe , with their foam filter , pro flow adapter and jet kit ... running no air box lid .

Would you run a 45 or a 48 pilot ?

I'm think a 48 pilot with the needle on clip #3 and maybe a 175 - 180 main and the air screw I haven't a clue .

What do you guys think ??

[Z-135]

Count from the top!

[Quad18star]

Originally posted by Z-135
Count from the top!

Thanks . :D

[YFZ#426]

Ok i just installed a 480 athena kit in my yfz. I have a full system hmf pipe and im doing the cam mod. I also run with the air box lid and a k&N filter. Can u tell me a base line for jetting. I am at 1200 ft. Thanks in advance!!!

[korniev]

Originally posted by 4TraxRider
If your totally in the dark, get a jet kit, they come with some instruction on where to start. if you know what your doing and what you want to do, then just get individuals, it's a ton cheaper.

Da best answer ever!!!!

[YFZ#426]

thanks pal. that was a great answer. All i wanted to know was how a 480 kit would change the jetting from a stock motor. Oh and jet kit recomendations SUCK.