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New to KTM, "New" Bike, Carb Setup Confirmation...

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sup...

...just picked up a clean, tricked out 06 400EXC, i'm in the process of set'n up the carb and do'n a full maintenance before i start ride'n it regularly.

the bike came to Tejas via Colorado so jetting is a concern :lol:

got the carb off...it has a aftermarket fuel screw(manufacturer?) and looks like an insert that smooths and/or increases the velocity the mixture into the engines intake...here's a pic.

DSC01832.jpg

okaaa...here wut i found in the carb

Main: 168

Idle: 42

Needle: OBTN 2nd Clip Position from the Top outta 7 Positions

Fuel Screw: ~1 1/4 Turns Out >Starts easy Idle Smooth/Peaks (All the way closed rough idle)

Accel Pump Diaphram: NOK 858 (has "button")

i'm operating from ~40-90F temps and ~sealevel to ~1000' (primarily Texas Gulf Coast)

the above seems reasonable but i'm not sure about the Needle/Clip or Pump Diaphram...

...any suggestions? ...i didn't really ride the bike much before start'n this maintanence project(concerned about lean jetting) but the bike ran pretty gud for the little bit of ride'n i did...it does take a little while to warm up.

TIA,

Kenzo

:banana:

P.S. i've probably gone throug the first 50 pages of posts of interest here on TT so i've got a pretty gud feel of wuts up...also iz spellz funny on porpose :banana:

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in the vernacular, "Aint nuttin" or "Awlrite"

with that said, you should have found the info you seek. A KTM requires a re-jet and mostly a needle change to run its best. KTMTALK.COM is also a good place for carb stuff and all that is KTM.

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in the vernacular, "Aint nuttin" or "Awlrite"

with that said, you should have found the info you seek. A KTM requires a re-jet and mostly a needle change to run its best. KTMTALK.COM is also a good place for carb stuff and all that is KTM.

actually...if i had found it(nether site) i wudn't have asked... :banana:

...haven't found doodley on the OBTN needle or the insert which takes the carb outlet from 40mm to ~35.5...but i don't believe it's stock :banana:

the diaphrams is stock w/ 2mm "button" and no mods to the pumper ether(i.e. o-ring)...

i guess i'll just order the JD Kit and Honda diaphram...

...at least i gave the carb a gud cleaning and inspection off the bike...changing the jets and needle will be easy buy just rotating it now. :banana:

:lol:

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I suggest you call JD and let the know about that insert. That is going to change the jetting requirements. Or you need to remove this to use the recommended JD setup sheet.

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I suggest you call JD and let the know about that insert. That is going to change the jetting requirements. Or you need to remove this to use the recommended JD setup sheet.

actually i'm gunna skip JD and get Keihin jets/needles...i've jetted several carbs on different bikes...

...plus i'm a cheap bastard :lol:

:banana:

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I said "SHOULD" have found it. I know you said you didnt.

I have re-jetted both my 4st without using a JD kit. I did buy the Honda diap and o-rings, external FS n such from him tho. Im not sure if the 400 will use the same series as the 450-525, but they use the OCEMP thru OCEMR needles with a 158-162 main. If that helps any.

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I just put a JD kit in my '07 400 XC-W and it works well. I think I should have just jetted it myself though. There was a thread recently that Dave Hopkins was talking about needles for the 400 RFS and there was one that gave more power earlier, his quote was with the JD when you pull 40% you get 40% and with a specific OBD needle when you pull 40% you get 60%. I like the bike, but for lofting the wheel over obstacles I'd rather have this needle (this might have been in the intake forum). Regardless of what you do the o-ring is mandatory!

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I said "SHOULD" have found it. I know you said you didnt.

I have re-jetted both my 4st without using a JD kit. I did buy the Honda diap and o-rings, external FS n such from him tho. Im not sure if the 400 will use the same series as the 450-525, but they use the OCEMP thru OCEMR needles with a 158-162 main. If that helps any.

Honda diaphram ordered, o-ring mod to follow...i assume the 45 pilot is a given at lower altitudes...that gives me about 10 choices of needles from Sudco's site(OBEVP in "sticky" not shown)...will get 155, 158 & 160 mains.

Thx Mike :banana::thumbsup: that's the info i wus look'n for.

I just put a JD kit in my '07 400 XC-W and it works well. I think I should have just jetted it myself though. There was a thread recently that Dave Hopkins was talking about needles for the 400 RFS and there was one that gave more power earlier, his quote was with the JD when you pull 40% you get 40% and with a specific OBD needle when you pull 40% you get 60%. I like the bike, but for lofting the wheel over obstacles I'd rather have this needle (this might have been in the intake forum). Regardless of what you do the o-ring is mandatory!

i need to find that thread :banana:

:lol:

P.S. ...the intake valves were at about zero lash from the PO :banana: ...it still started & ran well but now even better! :banana:

Edited by Kenzo

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found it...

http://www.thumpertalk.com/forum/showthread.php?t=878927&highlight=

Newmexican, the OCEMQ needle is not a KTM needle. The KTM needle is a OCB...which needs much larger main jets. The OCEM.. needles work with 158 to 162 mains never with a 185.
100% correct with one add on comment, the 3rd letter is taper and the "E" taper needle is used in the late model 250s so is available from KTM there.

An E taper would be a horrible gas hog with a 185 main!! Way too rich.

Back to the differences between E taper & JD taper

JD is a gentler taper so throttle action is very smooth linier power!

The E taper being steeper makes more power at part throttle, power may be the same at wide open but greater at say 1/3 rd open, result is the JD is better for managing traction in slippery conditions, the E taper will feal more agressive. How to explain better, when I said the JD power in "linier", that would be throttle 10% open = 10 % power, 40% open = 40% power, 100% open = 100% power

E taper might be 10% open = 10% power 40% open = 60% power, 100 % is still 100%

The last letter refers to the base diameter of the needle. So for instance the EMR needle has a slight thicker base diameter (leaner) than the EMP needle. This means that the EMR needle is slightly leaner from 0 - 1/4 (off idle) throttle than the EMP needle. Since both of these needles have the steeper 'E' taper, they need fairly small main jets from 158 to no richer than 162.

:banana:

:lol:

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from motorcyclecarbs.com...

9141 FCR N427-OC EMP JET NEEDLE 17.95

634 KEIHIN MAIN JET 99101-357 #155 6.95

635 KEIHIN MAIN JET 99101-357 #158 6.95

636 KEIHIN MAIN JET 99101-357 #160 6.95

535 KEIHIN PILOT JET N424-21 #45 7.95

Total 46.75

Thx guys! :banana::thumbsup:

:lol:

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I would also agree with Mike in Fresburg. EMP, ELQ, & EMR are all good needles to have in you quiver.

I would start with EMP #3, 162 Main, 42 Pilot, and tune from there.

Dave

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rejetted the 400 last night...it really woke it up! :thumbsup::thumbsup:

basically the motor is stock w/ the exception of the carb outlet insert that i haven't really been able to identify(see pic first page) :applause:

operating at sea level, ambient temps currently ~60-70F

Honda Diaphram installed & the O-Ring Mod done...

OCEMP needle w/ clip 3rd down

stock 42 Pilot Jet tests gud at 1.5 turns out on the fuel screw

158 Main Jet

the bike just keeps get'n better! :)

:lol:

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Perhaps that carb insert is one of Jeff Slaven's inserts?? I know that he does carb setups with special jetting and some type of insert for high elevation riding.

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Perhaps that carb insert is one of Jeff Slaven's inserts?? I know that he does carb setups with special jetting and some type of insert for high elevation riding.

gud call... :thumbsup:

Slaven did do the suspension :)

if to look at the carb closely, the throat at the slide is narrow and then the diameter opens up at the outlet...this device keeps it at a constant diameter to the outlet...i wud assume it keeps the velocity up.

thx...i'll check it out and may remove it.

:lol:

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from motorcyclecarbs.com...

9141 FCR N427-OC EMP JET NEEDLE 17.95

634 KEIHIN MAIN JET 99101-357 #155 6.95

635 KEIHIN MAIN JET 99101-357 #158 6.95

636 KEIHIN MAIN JET 99101-357 #160 6.95

535 KEIHIN PILOT JET N424-21 #45 7.95

Total 46.75

Thx guys! :thumbsup::thumbsup:

:lol:

You silly 'do-it yourselfers'!?!?

I bet if you just added up all your time, money, shipping cost etc it really is cheaper to just get the JD Kit! :applause:

One call, one bill, one shipment, all the parts you need and then some, etc...

Call me lazy! (...again)

I was out riding at lot quicker too! :)

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