GYTR Jet Kit vs. JD Jet Kit

[jams229]

I have now owned my 2007 WR 450 for 2 years - almost.

I have done a lot to it and it has been a great bike.

One area I would like to improve, however, is jetting.

Has anyone tried BOTH the JD kit AND the GYTR kit?

If so, please share the pros and cons of each.

- I purchased/installed the GYTR kit when I bought the bike.

It's good, but not great. I have fine-tuned it to death.

I had a JD kit in my '05 CRF450X, and it was flawless, and I have heard

from some that the JD kit for the WR is great as well.

Thanks for your comments,

Jim

[ranger85]

I have both and think the JD is hands down the way to go. What I like about the JD kit is that its really adjustable for all kinds of different conditions/altitude. The GYTR kit does good to, but I have the JD in there now and she runs suppper strong. I normally use the Red needle with the JD kit, but the blue needle is good for those super cold winter days or really low altitude. Of course the GYTR kit comes with all the extra stuff including the leak jet and air jet, which I don't have in now with the JD kit and she runs strong everywhere, no bog, stutter or anything. Now I did have the WR mid throttle stutter that lots of people talked about, from the first day I got the bike, and the only way I got rid of that was by unplugging the TPS. Strange. But, yeah if you do a lot of riding in different conditions, altitude, then I suggest the JD, if not, then you should be able to finetune that GYTR, but I still like the needles better on the JD.

[starfish]

Hey had the yamaha kit in my 07 wr 450 it ran fine. But the mileage was not great. Pulled the plug one day it was BLACK. Put jd kit in and runs great. Mileage improved about 2 miles per gallon at race pace.

[ophir]

JD was on the money with my bike, plus if you ever have any questions, he is easy to contact. Try that with GYTR

[BajaFool]

Jams229,

The GYT-R jetting for your bike is too rich. Jet it to the carb specs for the 2004 WR450F. I used the 2004 WR450F jetting specs in my 2006 WR450F and I currently have this jetting in my 2008 WR450F. The 2008 WR450f performs nearly exactly as the 2004 WR450F did with this jetting. The 2008 bike runs perfectly from sea level in the desert to 5,000+ ft in the mountains. The bike starts easily, has snappy throttle response and averages 40+MPG with stock gearing in a combination of tight single track, two track 4X4 roads and unimproved dirt roads.

Yamaha reworked the jetting in 2004, after the 2003 WR450F jetting was found to be much too lean. The 2004's ran very well stock out of the box and this was the last year before Yamaha re-reworked the carb to include lean jetting, a non-adjustable needle and the AIS equipment.

The 2004 carb specs you are interested in are #45 Pilot Jet, OBDWR Needle in the fourth clip position and a #165 Main Jet. Leave everything else in the 2007 carb alone and adjust your fuel air screw as needed. Assuming that you ride primarily in Maryland and over in mid-state Virginia, you do not have the altitude changes that we in the West have to deal with. You are most likely going to "set the carb and forget it". The JD Kit is a wonderful product and is great for the guy who has no clue how to jet a motorcycle or for someone who rides under widely varied conditions on a regular basis. In your case, I would not buy the JD Kit. Instead, I would recommend that you buy a couple of jets and a needle and then buy yourself a beer with the money you saved.

[jams229]

BajaFool - thanks for your response. I am surprised I have not heard this info before, so of course I am a little skeptical... Regarding the OBDWR needle you recommend, is it different than the needle that came with the GYT-R needle? If so, where do I get it?

ranger85 - did you notice any cons to disconnecting the TPS? I know there have been lots of posts on this, but I still have that annoying stutter at 55-60 mph, and even though I don't ride on the road often, when I do, it sucks.

Thanks again,

Jim

[ranger85]

So far I haven't noticed any cons with disconnecting the TPS. The bike runs super strong, maybe stronger, everywhere, fuel mileage seems the same. Theres a lot of dirt roads, and long flat trails out here in Utah, so I couldn't live with that constant stutter, plus I plan on throwing a dual sport kit on sometime soon. Theres really nothing to it, you can try it, and if you don't like it plug it back up, the connector is located right under the tank near the top of the valve cover on the left hand side of the bike(If your sitting on it). It's a white plug, you can follow the wire running straight to the TPS on the carb. Unplug it, try it, if you don't like it, plug it back up, it won't hurt anything.

[jobfnl]

Jim,

I installed the GYTR kit on my '07 first thing. Bike was way to rich, didn't want to strart..... Then spent the bucks on the JD kit, after months of swapping jets I ended up with 45 pilot, 165 main, and jd red needle 4th. clip.

Just like BajaFool says. I did all the free mods and the GYTR exhaust tip.

Would also get a good adjustable bronze fuel screw. This setting should put you about 1.5 to 2 turns out on the screw. Save your money, just buy the jets you need.

Jeff

[jams229]

I take it then that the JD Red Needle and the OBDWR needle that BajaFool recommended are the same needle?

And is there any way to use the existing GYT-R needle by simply changing the clip position?

Thanks again,

Jim

[jams229]

Thanks Jeff - I appreciate your advice.

Jim

[BigVthumper]

Jams229,

The GYT-R jetting for your bike is too rich. Jet it to the carb specs for the 2004 WR450F. I used the 2004 WR450F jetting specs in my 2006 WR450F and I currently have this jetting in my 2008 WR450F. The 2008 WR450f performs nearly exactly as the 2004 WR450F did with this jetting. The 2008 bike runs perfectly from sea level in the desert to 5,000+ ft in the mountains. The bike starts easily, has snappy throttle response and averages 40+MPG with stock gearing in a combination of tight single track, two track 4X4 roads and unimproved dirt roads.

Yamaha reworked the jetting in 2004, after the 2003 WR450F jetting was found to be much too lean. The 2004's ran very well stock out of the box and this was the last year before Yamaha re-reworked the carb to include lean jetting, a non-adjustable needle and the AIS equipment.

The 2004 carb specs you are interested in are #45 Pilot Jet, OBDWR Needle in the fourth clip position and a #165 Main Jet. Leave everything else in the 2007 carb alone and adjust your fuel air screw as needed. Assuming that you ride primarily in Maryland and over in mid-state Virginia, you do not have the altitude changes that we in the West have to deal with. You are most likely going to "set the carb and forget it". The JD Kit is a wonderful product and is great for the guy who has no clue how to jet a motorcycle or for someone who rides under widely varied conditions on a regular basis. In your case, I would not buy the JD Kit. Instead, I would recommend that you buy a couple of jets and a needle and then buy yourself a beer with the money you saved.

What pipe are you running w/ the above jetting? Also, did you remove the AIS?

[tribalbc]

You can buy the GYTR kit and a bunch of different jet's for the price of th JD kit.

Since I was removing the AIS anyways this kit made sense to me. Used the needle,leak and air jet. Ended up with a 168 main and 45 pilot. Now I have a couple spare different size pilot and main jets, no biggie

I guess for some people the JD needle works better but I've had no prob with the GYTR needle.

[jams229]

What pipe are you running w/ the above jetting? Also, did you remove the AIS?

Stock pipe with pea shooter removed.

AIS removed.

[BigVthumper]

thanks for the info

[jams229]

You can buy the GYTR kit and a bunch of different jet's for the price of th JD kit.

Since I was removing the AIS anyways this kit made sense to me. Used the needle,leak and air jet. Ended up with a 168 main and 45 pilot. Now I have a couple spare different size pilot and main jets, no biggie

I guess for some people the JD needle works better but I've had no prob with the GYTR needle.

tribalbc - thanks for your response. What clip position on the needle? Mine is in the 4th slot from the top, as recommended by the GYT-R kit.

I'm surprised that you are using a 168 main and 45 pilot with good results.

(I am using a 162 main and 48 pilot.)

Thanks again,

Jim

[tribalbc]

tribalbc - thanks for your response. What clip position on the needle? Mine is in the 4th slot from the top, as recommended by the GYT-R kit.

I'm surprised that you are using a 168 main and 45 pilot with good results.

(I am using a 162 main and 48 pilot.)

Thanks again,

Jim

Same needle position. I also have an 08 YZ exhaust though with PMB Endo SA and silent insert. I started with the GYTR main and pilot and worked my way down to where I am now. Fuel screw 1.5 - 2.5 turns out depending on elevation and weather. Runs clean and smooth everywhere, no hesitation or bog, no lean pop.

I ride between 1000 and 6000ft with this setup. It isn't optimum when I'm up high obviously but liveable. Probably ride in generally cooler temps than where you are.

[BajaFool]

Jams229,

The OBDWR needle and the GYT-R needle are not the same needle. The JD Red Needle is not the same as the OBDWR Yamaha needle. If you begin to introduce too many variables (i.e., after market pipes, altering the TPS, YZ needles etc.)into your jetting equation, you will soon have: (1) a mess on your hands; (2) a terrific headache or (3) both.

The OBDWR needle used in conjunction with the #45 Pilot Jet and the #165 Main Jet will work very well for any place that you will ride in Maryland and the surrounding states. If you need to jet richer, (possible if you are a really big guy and/or you ride a lot in the loose sand) you still have room for adjustment to go one notch richer on the needle, a #48 Pilot Jet, a #168 Main jet or possibly all three changes.

You buy carb needles for Yamaha motorcycles from the Yamaha dealer. Order the stock needle for a 2004 WR450F, (part number SKU: 5TJ-14916-WR-00 .NEEDLE (#DWR) STD), it is about $14.00 retail.

It is possible to buy needles from the Keihin Corp.. However, you need to be EXTREMELY well versed in carb theory or know which needle you want, using Keihin's identification system, when you talk to them. The Yamaha identification letters do not cross over to the Keihin identification system and it is too much trouble for them to make the effort to work out the crossover necessary to sell you their product, thus making a sale, a profit, earning a year-end bonus, perhaps a promotion, improving customer goodwill, gaining customers from Mikuni. Can you see that I did not like my experience with Keihin Corp.?

BigVthumper,

Along with using the jetting specs for a 2004 WR450F, I performed only the free mods that are listed in the GYT-R kit on both the 2006 and 2008 WR's, including the AIS removal mod on the 2008. The exhausts were original equipment on both bikes, except for the installation of the free mods. I did not actually buy the GYT-R kit for the 2008 WR. I made the aluminum blank off plate for the 2008 AIS removal, bought the rubber vacuum plugs at the auto parts store and bought the needle and jets mentioned above. I used the savings on the GYT-R kit for other accessories on the motorcycle.

[oldmanx]

Jams229,

The OBDWR needle and the GYT-R needle are not the same needle. The JD Red Needle is not the same as the OBDWR Yamaha needle. If you begin to introduce too many variables (i.e., after market pipes, altering the TPS, YZ needles etc.)into your jetting equation, you will soon have: (1) a mess on your hands; (2) a terrific headache or (3) both.

The OBDWR needle used in conjunction with the #45 Pilot Jet and the #165 Main Jet will work very well for any place that you will ride in Maryland and the surrounding states. If you need to jet richer, (possible if you are a really big guy and/or you ride a lot in the loose sand) you still have room for adjustment to go one notch richer on the needle, a #48 Pilot Jet, a #168 Main jet or possibly all three changes.

You buy carb needles for Yamaha motorcycles from the Yamaha dealer. Order the stock needle for a 2004 WR450F, (part number SKU: 5TJ-14916-WR-00 .NEEDLE (#DWR) STD), it is about $14.00 retail.

QUOTE]

Baja,

What is the difference between the stock needle in my 04 WR450 and the Yamaha OBDWR needle?

Right now my bike has a 165 main and a 45 pilot. It has an off idle bog when you get on the throttle. It has a Boyesen (sp?) AP cover and a 60 leak jet. I found the stock air screw to be 2.5 turns out, which from what I read is too much...indicating a need for me to do something with the pilot jet or the needle position...correct? I do have a JipTy air screw on its way. I was also thinking that I need to drop back to a smaller leak jet...something around a 40...correct?

Is there ever a need to mess with the starter jet?

And then to add confusion to the mix...which you said not to do...I received a FMF Q4 and a Powerbomb for Christmas. Should I go to a 168 main while I have it apart?

I ride mainly between 2,000' and 4,500' of elevation.

[Charles De Mar]

I have had better luck with the YZ needles in my 06 than the JD's. I've been back and forth and prefer the YZ needle. The JD needles are sitting on my shelf. I would save my money and try the YZ needle first. if that doesn't suit you then try the jd needles. I ran the JD needle for two years and find the bike starts better and runs in a wider altitude range with the yz. I would imagine the JD kit is more of an advantage to those that travel and ride in different places requiring jetting adjustments. Just my two cents.

[KennyMc]

I have the following mods done to my '07WR450

1) JD red needle on the 4th clip from the top

2) 168 Main

3) 48 Pilot

4) I used the other jets in the JD kit as well which I believe was a new leak jet but not sure

5) Snorkle removed

6) AIS removed

7) FMF Powercore 4TI slip-on

8) Throttle stop replaced

I ride from the CA desert at 2,500' to the mountains at Kennedy Meadows which got to 9,500' and I didn't make any adjustments. It has ran great with no bog or popping in any condition

I had all of these mods done before I ever rode the bike so I don't have a baseline to compare the performance to. For me, I have been very happy and haven't thought about tweaking it at all.