Keihin Carb set up?
 

Hi all, this is my first post (after much reading!) ref jetting my new (to me) 2007 EC250.

The bike "peed" out fuel so I have removed the Keihin carb (screw top so I think it is an AS1) and meticulously cleaned everything and set the float height as per the instructions on here. Throttle cable is set correctly. Air filter is clean with fresh oil and mechanically the bike seems sound. The fuel no longer leaks and the bike starts well but has an unreliable and erratic idle which I am unable to stabilise using the techniques listed on here. The air screw (pilot?) is 1 turn out (360 degrees) and the idle screw is nearly all the way in. It will idle fast ish.. but dies after a short while. The plastic idle screw is super sensitive to even a tiny movement.


The current set up is 172, 35 with a N1EF needle in position 2 (*7 slide)

Having studied the jetting database it appears that in the UK (sea level up to 2000 ft) most people seem to fit 180, 45, and an LTR needle. I intend to do the same but I am struggling to find an "LTR" needle for sale.

Can anyone point me in the direction of a UK jet needle supplier please? (and what to ask for!)

Also, the jets appear to be available on amazon for very little money... are they likely to be low quality or does it matter? (I was thinking about buying a selection)

Thanks in advance and no doubt I will have many more questions as I attempt to get this bike sorted out!

Regards
John

this is where the LTR needles originated https://www.lt-racing.com/ but not sure if you will find one. best is to find a ktm N3eh (or similar N3** needle) or for a more trils like feel the suzuki NEDJ (or similar NE** needle) The N1 was probably put in the GG bikes by a disgruntled employee with shares in ktm

Thanks Matt, the N3EH needle does seem to be available so I shall give it a try.

Ltr needle is a ddk

Do NOT buy jets off of Ebay. A lot are pure counterfeit, or even just cheap copies, but with their numbering system not meaning squat compared with real Keihin jets. Only buy genuine Keihin jets from a reputable shop like Jets-R-Us or the like.

If you have your idle speed screw turned almost all the way in then you are not idling on the idle circuit alone (main/needle is coming in to play which is not good). I would start with a pilot similar to what others have used for your elevation, adjust to see if it is correct for your setup (1 to 2 turns out on the air screw range, and get that sorted before even attempting messing with the needle or main jet. Everything starts with the pilot jet!

My 200 runs excellent and idles all day with a 42 pilot, 175 main and CEK needle at clip position #3. Air mixture screw 1-1.25 turns. It does have the RB divider plate and circuit mods, so this may affect the pilot selection. This setup has worked well for me from sea level to 2000 feet, rain or shine, without any adjustment.

A 42/45 pilot with a N3EG/H on clip #2/3 and a 175/178 main will be very close for you.

Thanks guys. Much appreciated

All ordered. :)

The float jet valve wears and replacement will fix you peeing issue permanently. My mates bike (2010 300) lost its entire load in my van overnight. I cant tell you how painful that all was.

Yabadabadoo....!
 

Update... (2007 EC250)

Firstly thanks to all for the useful and relevant advice, it is much appreciated.

My new needle arrived today and I now have the following set up...

178/40 (nearest I could get locally) N3EH (clip in the middle) - note: NEDJ is on order as well. (thanks Gasser Nate)

Yabadabadoo... unbounded joy! How can this bike have been ridden since 2007 with the original needle in it? It is transformed...truly transformed beyond all belief! I am delighted and amazed.

Firstly...it now has a steady tickover (hurray!) with (I think...) 1.4 turns out and the idle screw is not "spring bound" anymore. It is screwed in most of the way so maybe I need to try the bigger idle jet when my new ones arrive?
The revs hang slightly but after a few seconds things slow down to "sewing machine" territory.

The engine sounds as sweet as a nut and revs cleanly..SO much better than before.

I had a quick ride down the farm track (the bike is not road legal yet) and it rips... this thing will catch pigeons!!!

Everything is relative and, to me, it is perfect but no doubt I will need to do some fine tuning. The bike is also quite mellow and manageable at small throttle openings and responds well to throttle input without any snatchiness or drama but when you open it up it hits warp speed as quick as you can open the throttle. Love it..

I also fitted a new throttle slide because the old one looked a bit worn and some new gaskets from a service kit I bought from Ebay.

I have a few more cosmetic jobs to do but I think this bike will be a bucketful of fun.

PS.. Whilst waiting for the needle to arrive I decided to try and cure the annoying rattles the bike has. I replaced the power valve bearings and inserted a shim to reduce end float... wow.. that annoying rattle on the over run has disappeared. It still had a metallic vibration noise which I eventually identified was due to the exhaust touching the engine. Two new rubber mounts and careful positioning has stopped that annoying rattle as well.

Overall, I am very, very pleased and wish to offer my thanks to all for the wealth of information and guidance available here...

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