JD needles

It did not kick start very well and took quite a bit from the starter.

That isn't from the needle, thats the pilot jet doing that.

That isn't from the needle, thats the pilot jet doing that.

well my pilot jet just didn't like the JD's then cause the YZ needles lets it fire up. I'm putting the red needle back in:cool: with a #48 pilot and a 165 main jet. then I'm going riding in the mountains far far away from people. I may come back for my YZ needle though. Just a hunch:excuseme: I will not rebuild a bike around some needles. Even if it cost me whatever I paid for them. Besides that's not a very good Beezerism.

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Compared to a GYTR needle, the kit's Red needle will use a main jet of 4-5 steps bigger (#162 or #165 instead of #152 for example). The pilot jet size shouldn't be too much different, but would need the fuel screw adjusted.

--Hard starting when the motor is hot is a symptom of a rich idle mixture (pilot jet and fuel screw) or too rich of a needle clip position.

WR's usually have a good size pilot jet in their stock jetting, or enough to adjust with the fuel screw. The leak jet size is usually close too, but then the accelerator pump squirt preference varies widely from rider to rider based on how they ride. A stock KTM pumps about 10 times the amount of a CRF450X, and the WR's are in the middle.

Thanks,

James

See below-

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If you really want to jet the bike right you need a Merge adjustable leak jet and an adjustable fuel screw.

Changing leak jets sucks on a WR.

If you really want to jet the bike right you need a Merge adjustable leak jet and an adjustable fuel screw.

Changing leak jets sucks on a WR.

Anything other than the main jet is a pain :thumbsup: I'm tired of dinking with the AP timing, pilot jets ,leak, jets, main jets, red needle, blue needle, clip positions, tank on, carb off, carb on, tank on, tank off, carb off new clip position, main jet, pilot jet, needle position, carb on, tank on, tank off, carb off .....let the race mechanics bother with it.

The pilot jet isn't much harder than the main jet. I lay a small mirror on the case under the carb to see what I'm doing.

Charles, I just got my '08 back from the dyno yesterday. This bike is now a missile! Starts instantly, NO STUTTER AT ALL, no front tire on the asphalt through ALL the gears, no overheating, etc. For the first time since I bought this bike it was close to scarring me last night!

In another post I had worked the stutter down to cam timing or jetting. It's ALL jetting. I know JD has shown some ignition spikes in his tests, but in the end IT WAS THE JETTING on my bike.

I'm at 5300' and my main jet is now a #152, "mystery needle" from the GYTR-AIS removal kit is now on 2nd from the top, OEM main air jet is 2.0, and all else in the carb is OEM stock. I'll try to head for higher ground this weekend and see how she does, but right now it's really tough to hold on to!:thumbsup:

Thanks for the post. add it to the Jetting database for others.

The pilot jet isn't much harder than the main jet. I lay a small mirror on the case under the carb to see what I'm doing.

Is that the same mirror you use on your shoe at the bar?

Thanks for the post. add it to the Jetting database for others.

I will, but first I want to take it above 12,000' to see how it does.:thumbsup:

I have not put in my JD kit in yet.

i am @ 780feet elevation.. and my bike runs awesome...

being a 08 model been a little lazy on trying to get to the carb.

but maybe its time i tried and see what happens :thumbsup:

cheers

P.S good luck with your jetting woe's

Warts

I will not rebuild a bike around some needles. Even if it cost me whatever I paid for them.

I don't get it, JD already offered you a refund which you declined. so why are you still complaining about the purchass price? I could undrstand complaining about the wasted effort, which is sizeable on thease bikes.

The three JD kits I’ve installed work great on three different 08WR450s. a definite improvement over stock and AIS jetting. From sea level to 7000 feet, works fine with just the twist of the fuel screw.

Could a YZ needle be better:excuseme: don't know, but with the JD recommended settings, I've never experienced anything that made me desire a change.

I don't get it, JD already offered you a refund which you declined. so why are you still complaining about the purchass price? I could undrstand complaining about the wasted effort, which is sizeable on thease bikes.

The three JD kits I’ve installed work great on three different 08WR450s. a definite improvement over stock and AIS jetting. From sea level to 7000 feet, works fine with just the twist of the fuel screw.

Could a YZ needle be better:excuseme: don't know, but with the JD recommended settings, I've never experienced anything that made me desire a change.

I mean I'm not going to buy an ignition mapping system to adjust for the surge that the JD needles seem to emphasize. I used the needles for two years, I don't think he owes me anything. I just replaced them like I would handle bars, sprockets or plastic. I'm just getting others to think about what the really want. that's all. I didn't say "don't by these it will be a mistake" That's what is good about this forum, I'm allowed to post my experiences and what I have done for others to make decisions with. It's free speech.

I mean I'm not going to buy an ignition mapping system to adjust for the surge that the JD needles seem to emphasize. .

JD needles emphasize the surge:confused: the stock needle and the WR AIS kit needle have the surge too. why the spin?

BTW, my surge went away when I intsalled a yz head pipe. :thumbsup:

I have fitted a JD kit to mine and 3 other mates WR450's here in the UK and everybody is happy, I couldn't recommend them enough :thumbsup::worthy::busted:

Charles De Mar,

Great topic. I just bought a new 2008 WR450F and will take delivery in 2 weeks. I currently own a 2006 WR450F and I went through the process of jetting that bike, I have been searching for some information that will help me when I take delivery of my new motorcycle.

I installed the Yamaha AIS kit in my 2006 WR450F and performed all of the free mods (changed throttle stop; removed AIS and snorkle; disconnected gray wire; drilled out the airbox and opened up the muffler). The 2006 AIS kit came with a GDDT-R needle set on #4 clip position and a #48 Pilot Jet, with the air screw setting specified at 1 1/2 turns out. The #50 Leak Jet and #165 Main Fuel Jet were left stock. The bike ran great from a little under sea level (near El Centro in the S. California desert) to 4,500 ft in the N. Baja California, Mexico mountains. It was an easy starter first thing on a cold winter morning at 3,000 ft. I did not think that it got as good gas mileage as my 2003 WR450F , however. I was getting in the high 30mpg with the 2006 on long trips in 5th gear. On similar trips on the 2003, I could get 50mpg. The 2003 was however, a hard starter when it was cold with the stock #45 Pilot Jet. I changed the jetting on the 2006 to the stock jetting for a 2004 WR450F. The 2004 jetting is #165 Main Jet, OBDWR-4 Needle, #45 Pilot Jet and a #60 Leak Jet. The bike picked up gas mileage, now on a long 5th gear ride, I get in the mid-40s for mpg. It is hard to start on a cold winter morning, however.

So, here are my thoughts on jetting our WR450F's. My experience is that the 2004 WR450F jetting is a very good choice, but perhaps use a #48 Pilot Jet instead of a #45 Pilot Jet.

Finally, Dirt Bike, in the March 2007 Issue tested the 2007 WR450F. Their conclusion was to do the free mods and leave the stock jetting in the bike, which included a #162 Main Fuel Jet, the non-adjustable needle and a #45 Pilot Jet. They stated that the bike worked great up to 7,000 ft and got outstanding gas mileage. I have a friend who followed their jetting guidance and he confirmed their findings. The bike ran fine in the desert at sea level (he is a mechanic and performed a spark plug reading) and ran fine at 4,000 ft. It starts easily and "makes" gasoline.

So, what do you all think I should do for jetting for my "not yet in my garage" 2008 WR450F, which will be ridden at 3-4,500 ft. the vast majority of the time. The 2004 WR jetting, the stock 2008 WR jetting or the stock 2008 WR jetting with a STD 2008 YZ450F needle and set on which clip setting?

On the 2008 WR450 which is really the same bike as a 2007 Dirt Bike used a DR D. pipe with an NCVQ#4 needle.

Which means they sat around an picked their noses while Dr. D. did all the work.

Beezer,

Sorry, I got my magazines mixed up. The article was in Dirt Rider, October 2007. The bike, other than the free mods, was left stock, This included leaving on the AIS. READ BELOW:

What follows is the excerpt from the October 2007 Dirt Rider 450 shootout article entitled 2007 450 Off-Road Comparison: "Making the Yamaha Run. It is pretty easy to make the WR go from snore to score. Just buy the GYTR kit (GYT-5TJ93-69-01, $49.95) that includes the shorter throttle stop, a block-off kit for the Air Induction System (AIS) and a set of jets that bump the power by richening the jetting, then follow the included instructions. This is how we tested the bike in Costa Rica for its debut and in our first test. But in light of current standards and enforcements here in California, we also came up with the setting that we tested the bike in for this comparison. We used the shorter throttle stop, took out only the smallest stuffer from the muffler and removed the restrictor from the top of the airbox. We also disconnected the gray wire at the six-pin connector underneath the left sidepanel. We left the stock jetting in the bike and did not mess with the AIS, as it has no performance effect on the engine aside from causing the lean popping noises inside the exhaust. With this setting, we felt the bike was more ridable and smoother in the smaller throttle positions than the GYTR-jetted bike, and it got better fuel economy. Plus, it ran better at elevations above 7000 feet."

So, what about the 2008 YZ450F needle for the 2008 WR. Do we think the STD needle? What clip and what other jets and sizes to go with the new needle.

Beezer,

Sorry, I got my magazines mixed up. The article was in Dirt Rider, October 2007. The bike, other than the free mods, was left stock, This included leaving on the AIS.

I also read that article… and I ran the stock jetting with the free mods on My 08WR for a while. But the glow in the dark header pipe had me worried about how lean it was running. But It ran OK for me , but did not for my buddy’s identical 08WR (we ride together, bought them together and they are 3 serial numbers apart), he had a really bad bog.

he’d grab some throttle and the bike would die and he’d dump the bike.…… :thumbsup:

we tried the WR AIS needle and a 165 main jet, with a thin O-ring and he was still complaining. then I helped him install the JD kit with a zip-ty fuel screw, we used the thicker O-ring from the kit and he hasn’t complained about it yet.

He’s even convinced himself that his bike runs better then mine…. But that is BS, mine runs better:busted: .

Was it the fuel screw or the O-ring or ????? I don’t know. But the morel of the story is that the stock jetting might work or it might not work.

But the morel of the story is that the stock jetting might work or it might not work.

:thumbsup: Amen

It has been suggested that the 2008 YZ450F standard needle (#NFLR), #165 Main Jet and a #48 Pilot Jet are a good all around pick for the 2008 WR450F. This combination has been suggested, because you can work around all of the parts of the Yamaha AIS kit. Out of the Yamaha AIS kit all you want is the needle in the kit. You don't need the too rich jets and you can make a metal blank off plate out of thin aluminum, buy vacuum hose plugs at the auto parts store and cut the stock WR throttle stop to the YZ specs from the info on Thumper Talk also. The directions for the free mods are on Thumper Talk, so why spend $50 for a carburetor needle. What have I missed in my reasoning?

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