Author Topic: KTM 250sx jetting  (Read 1845 times)

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Offline motox11

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KTM 250sx jetting
« on: April 22, 2013, 05:35:44 AM »
I plan on doing a 39mm oval bore with my ktm 250 this week instead of keeping the 36mm stock bore. instead of playing around with jetting, i was wondering if anybody had some good jetting specs that they could share with me to save time or at least point me in the right direction. The elevation is about 1000 feet for my area.

Offline Jeram

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Re: KTM 250sx jetting
« Reply #1 on: April 22, 2013, 07:22:43 AM »
I wouldnt be copying anyone unless they have the same mods, temp and elevation.

For something as technically specific as this, I would try KTMtalk's 2 stroke section, they have some great jetting threads on there.

Offline Stusmoke

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Re: KTM 250sx jetting
« Reply #2 on: April 22, 2013, 08:56:31 AM »
Also check out ****sracing's intilijet carb mod for the 250sx or whatever it is. MXA had some sweet results with it apparently. Link here: http://motocrossactionmag.com/KTM/News/INSIDE-MXAS-WORKSHOP-BUILDING-THE-ULTIMATE-2012-KT-8964.aspx
See you in Hell or Motocross Des Nations, whichever I get to first.

2013 KTM 250SX

2001 Honda CR125

Offline maicoman009

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Re: KTM 250sx jetting
« Reply #3 on: April 23, 2013, 11:58:49 AM »
Also check out ****sracing's intilijet carb mod for the 250sx or whatever it is. MXA had some sweet results with it apparently. Link here: http://motocrossactionmag.com/KTM/News/INSIDE-MXAS-WORKSHOP-BUILDING-THE-ULTIMATE-2012-KT-8964.aspx
As you mentioned on here Stusmoke I would most definitely get a Intellijet carb from ****s Racing! I recently rode a 2009 KTM-250xc-w & the jetting & power was near perfect if not perfect!!! I believe the Intellijet carb runs about $485.00 give or take,but they are well worth that price imho!!! ;)

Offline Stusmoke

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Re: KTM 250sx jetting
« Reply #4 on: April 23, 2013, 02:43:33 PM »
Also check out ****sracing's intilijet carb mod for the 250sx or whatever it is. MXA had some sweet results with it apparently. Link here: http://motocrossactionmag.com/KTM/News/INSIDE-MXAS-WORKSHOP-BUILDING-THE-ULTIMATE-2012-KT-8964.aspx
As you mentioned on here Stusmoke I would most definitely get a Intellijet carb from ****s Racing! I recently rode a 2009 KTM-250xc-w & the jetting & power was near perfect if not perfect!!! I believe the Intellijet carb runs about $485.00 give or take,but they are well worth that price imho!!! ;)

I don't understand how it works but its been met with glowing reviews.
See you in Hell or Motocross Des Nations, whichever I get to first.

2013 KTM 250SX

2001 Honda CR125

Offline Micahdogg

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Re: KTM 250sx jetting
« Reply #5 on: April 23, 2013, 09:51:11 PM »
I heard the intellijet turns into a leaky mess in short time.  That (more than price) is holding me back. 
2011 KTM 250SX, 1986 ATC250R

Offline rlaj1004

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Re: KTM 250sx jetting
« Reply #6 on: April 23, 2013, 10:12:23 PM »
I have ****s racing counter bore and the intellijet on my 250SX. It is fantastic. Not sure how it changes the power curve but it feels like it hits a second gear within the gear. When it comes on if I am hard on the throttle it will pull the wheel off the ground in 3rd and 4th. You also can change the jetting with a simple dial based on temp or elevation. And yes it is pretty much right at 500, was worth it to me.

The advantage of what they do is they leave the opening 36 and conter bore it to 39 so you have less jetting, idle issues with the added power of the larger bore.

Never heard it becomes a leaky mess, mine is not, but I am pretty meticulous with maintenance.
09 KTM250SX. 02 CR125R, 00 YZ250, 02 YZ125, 03 YZ 85 and a Harley :-)
It takes, as Roger DeCoster noted, more talent to ride a two-stroke