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Ak Yammy

Dynojet vs. JD kit

16 posts in this topic

True, they are cheaper, but try speaking to the guy that developed it if you have a question or problem or even anyone who really knows what they are taling about. You do get what you pay for.

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True, they are cheaper, but try speaking to the guy that developed it if you have a question or problem or even anyone who really knows what they are taling about. You do get what you pay for.

agree…..

If you want a big bag of jets and you just want to fiddle around…. then the JD kit is not your best value, there are cheaper ways to buy jets. Unless you wanted to try JD’s needle taper.

The JD kit is the easy button. The kit comes with jetting recommendations and they worked good enough for me. JD kit also comes with 2 custom tapered needles, which I think is very important. Swapping out jets is not such a big deal for me to wrap my brain around, but try to figure out needle tapers was just too complicate for me to deal with.

And If you have issues, just send him an email. It just makes the whole thing really simple. He dyno tests his kits before he releases them.

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Sold me on the James Dean. I've had to put enough work into this bike as is. Not complaining mind you worth the effort and thanks to all on this site I was able to do the water pump fix and diagnose an electrical problem. JD it is Thanks guys!!

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Im glad i went with the JD kit myself. The new wr is not the easiest bike to work on and wanted it done once and right

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I had a Dynojet kit installed as per instructions on my 07 wr450....no where near...eventually gave up with it and bought some jet replacements. JD would be the way to go in my opinion.

now running a 168 main and std needle which is good. I have a FMF Powercore on her.

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I had nothing but hell with dynojet, tried everything the instructions said, several time, every time i tried different settings is was still bad, got a jd kit from the yamaha shop installed as per instructions for my altitude and it started and ran PERFECT!

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I had big luck with my jetting, went to my local dealer and asked if he had any jets for the 426, he said yes there was a guy competing in enduro that ordered about 3 sizes bigger and 1 size smaller of all jets and needles compared to stock, I would get it for about half price since it been laying around for a while.

So now I have a lot to choose from depending on temperature and so on.

It's fun to test different setups and see how it effects the performance.

I' have made some marks on the throttle handle to see in what range the throttle is when the engine feels in certain way to know what to jet.

I think there should be no lag, bog, or hesitation at all no matter what position your throttle is in and you open it WOT as long as you are in normal rpm's.

Does any of those kits (JD-DJ) deliver that performance?

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I think there should be no lag, bog, or hesitation at all no matter what position your throttle is in and you open it WOT as long as you are in normal rpm's.

Does any of those kits (JD-DJ) deliver that performance?

If I'm at idle in neutral and rip the throttle real fast, I can get my engine to die. :thumbsup: It's never happend when I'm in gear or actually riding the bike.

and I do have the normal WR surge with steady slow speed. and I get some poping on deceleration from the AIS.

besides that it rips.

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If I'm at idle in neutral and rip the throttle real fast, I can get my engine to die. :thumbsup: It's never happend when I'm in gear or actually riding the bike.

and I do have the normal WR surge with steady slow speed. and I get some poping on deceleration from the AIS.

besides that it rips.

Maybe only open pilot screw slightly.

I understand many people are satisfied with JD-kit, and only needs small adjustments for a perfect running bike.

It's probably cheaper to buy that kit than a bunch of stock jets 'n needles in various sizes and try your way to "the perfect setup" but I actually think it's fun and very educational to tinker with the jetting so I'll stick to try my way ahead.

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Maybe only open pilot screw slightly.

.

I can rip the throttle as fast as I want if the bike is in gear... just not in neutral. If I cared about engine performance in neutral… I'd install the thicker O-ring, which came with the JD kit.

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I can rip the throttle as fast as I want if the bike is in gear... just not in neutral. If I cared about engine performance in neutral… I'd install the thicker O-ring, which came with the JD kit.

I dont care about engine performance in neutral either but I thought it sounded strange that you cant rip it in neutral if you can do it in gear.

Do what you want, keep it as you want, rip it as you want.

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I had a Dynojet kit installed as per instructions on my 07 wr450....no where near...eventually gave up with it and bought some jet replacements. JD would be the way to go in my opinion.

now running a 168 main and std needle which is good. I have a FMF Powercore on her.

I'm looking at using JD kit after having success with it on my 426. How did you find the Powercore? One of the biggest things i've notices sinced upgrading to an 08 450 is the power seems to be in the middle only and flattens out a lot earlier than my 426 would. I have to keep upshifting to keep it in the power.

Is this a chocked up emmissions/exhaust problem or just need a new pipe and jetting?

i've replaced the standard throttle stop, removed airbox snorkel, and put GTYR exhuast tip in muffler. still got same problem.

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I had the same deal, i used that gytr tip too, and belive me a new pipe is the single best thing you can do to a new wr, i got a fmf factory 4.1 carbon and i could not belive what a diff it made, a month or so later i ended up getting it jetted correctly, and that was a huge improvement too, good luck

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The main advantage to the JD jet kit, other than the fact JD figured out everything and provides simple to follow directions is the needle. Stock needle are a single taper design. You have to comprimise between (approximately) 1/4 throttle and 3/4 throttle jetting. JD's dual taper prodifes a more accurate jetting at 1/4 and at 3/4 due to the dual taper. You cannot buy needles like this from anywhere but JD as he makes them in house. The included main jets, leak jets, pilots are all standard jets available anywhere. JD includes them so you do not have to hope to be lucky with your local parts monkey. Depending on the carb kit, he also includes other things if needed.

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I had the same deal, i used that gytr tip too, and belive me a new pipe is the single best thing you can do to a new wr, i got a fmf factory 4.1 carbon and i could not belive what a diff it made, a month or so later i ended up getting it jetted correctly, and that was a huge improvement too, good luck

I'd have to agree. on my 08WR, even after I did all the free mods and jetted and had the GYTR tip. My loevince slip-on (even in 94db mode) made a very noticable increase in low end power over the stock silencer. :thumbsup: but...the stock pipe is real good at being quite.

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