What main/idle jet shold I choose?

[Kimpan]

I have a 625 SXC converted into a supermoto. I have a sebring hunder slipon on it and am now going to get rid of the SAS as well as open up the air box and unhook the "CA"? and "TPS"?.
I will probably need to rejet my carb now that I get more air in, right?
What main/idle should I go for?
I believe I have the original needle in the carb.

[tdreyer]

What year? What carb? Check out JD jetting for the FCR and somewhere there is a thing called the BST Bible. I'll see if I can dig it up.

[tdreyer]

Here it is.. http://ktmtalk.com/index.php?showtopic=290325

[Kimpan]

It's a 2005 so it has a Keihin FCR41 carb. Since it is SXC it has a single exhaust.
I thought I'd wait with buying the JD jet kit since it costs ~$125 here in Sweden whereas new main/idle jets would cost me ~$10

would 168/48 be a good guess with slipon+open airbox?

[tdreyer]

My jetting was 170 with the obekr needle installed with the clip in third form the top. 45 pilot. My JD kit for sea level recommends a 170 and a 45 pilot. JD's needles are a cross of Keihin needles but my obekr and the ocemr seem to be the picks. Depending on temp and elevation all of that will change. With it being winter my temps being 20's - 50's F I had a 172 MJ and the clip in the 4th from topto richen it up. On the really cold mornings it was probably a little lean. I have little chance of snow or ice so I can ride every day.

[Kimpan]

I will try 170/45 then!
What needle is there originally in the FCR41? Should i change to a OBEKR?

[tdreyer]

I had good success with the OBEKR. From what I've read the stock US needles are very lean, emissions thing. Not sure if you would have the same issue or not. Everything I'd read about jetting suggested the OBEKR. If you can go to KTMtalk and look in the Hot Topics Forum: Jetting 2 and 4 stroke. Look here http://ktmtalk.com/index.php?showforum=10 will be a lot of info but if you search you can find some other suggestions on needles. I see a lot of guys running 175 and up MJ but I believe that is because they are trying to overcome a very lean needle. 170 to 172 should be as big as you need depending on how cold you want to ride. 168 is probably the leanest for hot temps. All the rest is the needle and clip position. The big popular opinion is to use the JD kit but you are $mart to go with the cheapest route. My 170 and OBEKR needle is very close to my new JD 170 w/blue needle 3rd clip.