Red needle confusion

[AZmaxxed]

Just picked up a 96 that has a JD red needle in it, jetted 45/162? It’s got an FMF exhaust and airbox opened, around 2,000 feet originally. I’ve seen ranges from 148 to 165 on the main, and 38-45 on the pilot while using this needle. Why does JD recommend so rich, and how do some guys end up super lean? I compared an 1174 to the red needle with calipers, the red is quite a bit richer which would imply using a smaller main than stock? I’m at 4,000 feet, gonna try 42/155 and go from there…

[John_S]

It’s been a long time since I got my JD kit and forget whether or not it suggested a pilot size. For my 220 their main Jets were too rich. Try setting the float height to 18mm instead of 15mm. This doesn’t have anything to do with the JD needle but a lot of guys seems to like it. It helped my bike a lot.
Once it was all set that red needle is amazing. Noticeably better than stock, DEK or CEL on my bike. I’m at sea level but hot humid weather. With a 35 air striker its best with a 40 pilot, 2nd clip from the top, and a 145-148 main, air screw 1.25 -1.5 turns out.

[kdxdazz]

I wondered this too, my kdx220 runs so rich at idle that It won't idle with the JD red needle, the JD needle is slightly richer on the taper too, I have no idea who this needle suits and to be honest I think it's garbage, straight diameter is 2.725 compared to 1174 of 2.74, I tested the JD needle with 3 different carbs too and all super rich and that's using E10,I'm in Thailand where it's hot and humid, 1175 is my needle of choice
I spent years on here asking for jetting recommendations all.of them were so far off the bike wouldn't even idle and used gasoline like a V8 engine,

[John_S]

Kdxdazz, I remember all the posts you had about your rich idle and trying to work with worn out used carbs and grinding your own needles. There are so many needles that a brand new PWK would idle perfect with on a KDX. I live in hot, humid Florida and I could throw in a stock needle, CEL, DEL, DEK, JD blue or JD red and have it start one kick and idle just by messing with the air screw a little. The needles were never your problem.
One ride on my bike and you’d see exactly how well suited the red needle is. I don’t know if it’s still on this site but there was about a 110 page thread on needles and JD was a big part of those discussions. He used all that info to develop the KDX needles.
Did you ever end up getting a brand new genuine Keihin? At one point I thought you were even working with one of those $40 PWK’s off of eBay and complaining it won’t idle with any needle.

[kdxdazz]

Kdxdazz, I remember all the posts you had about your rich idle and trying to work with worn out used carbs and grinding your own needles. There are so many needles that a brand new PWK would idle perfect with on a KDX. I live in hot, humid Florida and I could throw in a stock needle, CEL, DEL, DEK, JD blue or JD red and have it start one kick and idle just by messing with the air screw a little. The needles were never your problem.
One ride on my bike and you’d see exactly how well suited the red needle is. I don’t know if it’s still on this site but there was about a 110 page thread on needles and JD was a big part of those discussions. He used all that info to develop the KDX needles.
Did you ever end up getting a brand new genuine Keihin? At one point I thought you were even working with one of those $40 PWK’s off of eBay and complaining it won’t idle with any needle.

this is the kind of response i expected and all i ever got when asking jetting questions, the needles were the problem, they were too rich on the straight diameter which is now why i now use an 1175 with none ethanol fuel, i genuinely believe jetting bikes close to the equator with altitude thrown in to the equation is different to other parts of the world , i was told my carbs were worn out but it wasn't the case and just to show how indepth i researched it, ive attached a photo of testing emulsion tubes at a technology university using a mituyo light meter, if you can find another person that went to such great lengths , the rb carb wasn't worn out, the chinese pwk was of excellent quality and the emulsion tube was within 0.01mm accuracy, and that was to the lean side, i also tested another genuine pwk with the same tolerances, my point being if people are complaining a JD red needle is rich people shouldn't keep repeating "nothing wrong with the needle"
having said all of this i have purchased a 34mm lectron with a 3-2m needle which i hope will be a success

[KDXGarage]

kdxdazz, good luck with the continuing search. I think you have a unique set of parameters to the environment.

[John_S]

Kdxdazz, I posted above how well my bike runs and your response was I have no idea who this needle suits and that it was garbage. I spent a lot of time out of the lab with different jets and needles tuning the bike. When I can walk outside and it would start first kick, idle great, easily get 5 hours of engine run time trail riding, have no lean bogs or rich stutters at any throttle position…Of course my 2nd response is what you’re going to get.
I hope the Lectron finally gets your bike where it needs to be. Let us know the results.

[SS109]

Now that's what I call really digging and doing some research! Love to hear all of what you discover!

[kdxdazz]

kdxdazz, good luck with the continuing search. I think you have a unique set of parameters to the environment.

Correct, there are 195 countries in the world many with unique environments, glad I'm not in Nepal asking the internet gurus for jetting advice

[bufftester]

Correct, there are 195 countries in the world many with unique environments, glad I'm not in Nepal asking the internet gurus for jetting advice

Well, the best thing would be to run through the jetting process correctly (it works everywhere every time when done correctly) and then share your results for others who may be in similar environments and leave it at that. the bulk of users on here will rarely see some of the extremes you will have in jungle climes, and so their jetting requirements will be different. Keep in mind that 2 identical bikes at the same place can have slightly different jetting setups, so putting in the work to find yours is really crucial to fine tuning your bike, especially since none of our bikes are in new condition at this point.