2 stroke tuning advice

Sharpe325
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140
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6/6/2018
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Graysville, AL US
7/3/2018 6:02pm
Im not a carb expert but what do yall suggest im running a little rich and would i cure it with a air/screw adjustment or jet/needle. The bike is 2018 ktm 250sx and ive done the initial break in and it runs great just a tad on the rich side. And if it helps im in alabama and its hot,humid,and muggy. Im also running the reccomended 60:1 with motorex oil.
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mx510
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1973
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2/26/2011
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Gig Harbor, WA US
Fantasy
1861st
7/3/2018 7:14pm
JD jet kit bud, it’s a great addition to the bike.
Sharpe325
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6/6/2018
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Graysville, AL US
7/3/2018 7:32pm
Thanks man im gonna look into picking up that kit.
wpark89
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12/9/2009
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Mattawa, WA US
7/5/2018 9:18am
I don’t see the point of buying the JD kits? Enough jets come with your KTM tool kit to dial it in.

Do a search to learn a bit about jetting. Turning your air screw out (more air) will lean it out off idle (when you first crack the throttle). I’d guess you need a leaner pilot jet (I had to go smaller on my 250 SX a few years ago to get it crisp).

If it’s rich in the middle lean it out with moving your needle clip and if it’s rich when you’re wide open that’s the main jet.
1
riv187
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Lakeland, FL US
7/5/2018 10:44am Edited Date/Time 7/5/2018 10:47am
I own 2 huskys. '17 TC250,18 TC125. Like the KTM, they both suffer from off idle richness. You can chase it with smaller pilot and have hanging idle or different needles and still not hit the source of problem...the main cure is 5.5-5.75 slide. Or grind out your 4.0 slide like I've done on mine,,or have others cut yours to those specs...lots of other jetting threads that found this cure. Search here for TC250 jetting thread and AJ565 who posted a good combination I use in Florida https://www.vitalmx.com/forums/Tech-Help-Race-Shop,42/17-TC250-Jetting-…
1

The Shop

Sharpe325
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140
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6/6/2018
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Graysville, AL US
7/5/2018 6:07pm
riv187 wrote:
I own 2 huskys. '17 TC250,18 TC125. Like the KTM, they both suffer from off idle richness. You can chase it with smaller pilot and have...
I own 2 huskys. '17 TC250,18 TC125. Like the KTM, they both suffer from off idle richness. You can chase it with smaller pilot and have hanging idle or different needles and still not hit the source of problem...the main cure is 5.5-5.75 slide. Or grind out your 4.0 slide like I've done on mine,,or have others cut yours to those specs...lots of other jetting threads that found this cure. Search here for TC250 jetting thread and AJ565 who posted a good combination I use in Florida https://www.vitalmx.com/forums/Tech-Help-Race-Shop,42/17-TC250-Jetting-…
Thanks for advice wspark89 and riv187 im gonna play with it and see if i can lean it out just a tad. Im gonna read the tc250 jetting thread. I really appreciate the help on it because im not carb smart.
AJ565
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3/12/2012
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San Antonio, TX US
7/6/2018 6:36am
As riv187 said, we've had really good luck with the jetting in the thread he posted the link to. It's a night and day different bike from stock to the rejet. I also have a build thread on my bike and posted the jetting there as well. Its a 2018 250sx like you're riding.
Sharpe325
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Location
Graysville, AL US
7/6/2018 8:20am
AJ565 wrote:
As riv187 said, we've had really good luck with the jetting in the thread he posted the link to. It's a night and day different bike...
As riv187 said, we've had really good luck with the jetting in the thread he posted the link to. It's a night and day different bike from stock to the rejet. I also have a build thread on my bike and posted the jetting there as well. Its a 2018 250sx like you're riding.
Thanks man i really appreciate and im gonna check out your build thread.
7/6/2018 8:27am
Sharpe325 wrote:
I really appreciate the video link this will help me out a ton.
I really appreciate the video link this will help me out a ton.
No problem!! Check out the other videos on Cameron's channel... they're really well put together and informative as hell
1
Sharpe325
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Graysville, AL US
7/6/2018 10:28am
Sharpe325 wrote:
I really appreciate the video link this will help me out a ton.
I really appreciate the video link this will help me out a ton.
No problem!! Check out the other videos on Cameron's channel... they're really well put together and informative as hell
No problem!! Check out the other videos on Cameron's channel... they're really well put together and informative as hell
I will most def check his other videos out im always willing and trying to learn new things on these bikes.
AJ565
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San Antonio, TX US
7/6/2018 12:11pm
Turn the power valve all the way out and then back in 1 3/4 turns. Made the bike way more rideable. That with the right jetting and pipe/silencer combo really make the bike come alive.
Sharpe325
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140
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Graysville, AL US
7/6/2018 1:26pm
AJ565 wrote:
Turn the power valve all the way out and then back in 1 3/4 turns. Made the bike way more rideable. That with the right jetting...
Turn the power valve all the way out and then back in 1 3/4 turns. Made the bike way more rideable. That with the right jetting and pipe/silencer combo really make the bike come alive.
I will do that also. I really appreciate all your help and advice. This is my 1st brand new 2stroke because all my others has been used that was already tuned and jetted and i didnt have to mess with the carb a whole lot.
riv187
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Lakeland, FL US
7/7/2018 6:38am
While I think the Lectron could work well,they are not cheap....I once had a 'Predator' on my street car years ago...and Hilborn Injections on my race cars...like any of them,,they all cost money and have learning curve...nothing is perfect out of the box and all needs systematic tuning. The Mikuni we have will work great and make power...and is already paid for....spend $60 for some brass and 30 minutes with a dremel tool or approx $30 with RK to cut yours. Always when you swap carbs...there are other things that need farting with,,cables,inlet boot, throttle...Running the basline AJ and others hit tuning is cheap and easy. A big THANK YOU to AJ565 and Slipdog for sharing there experiances.
Sharpe325
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140
Joined
6/6/2018
Location
Graysville, AL US
7/7/2018 11:48am
riv187 wrote:
While I think the Lectron could work well,they are not cheap....I once had a 'Predator' on my street car years ago...and Hilborn Injections on my race...
While I think the Lectron could work well,they are not cheap....I once had a 'Predator' on my street car years ago...and Hilborn Injections on my race cars...like any of them,,they all cost money and have learning curve...nothing is perfect out of the box and all needs systematic tuning. The Mikuni we have will work great and make power...and is already paid for....spend $60 for some brass and 30 minutes with a dremel tool or approx $30 with RK to cut yours. Always when you swap carbs...there are other things that need farting with,,cables,inlet boot, throttle...Running the basline AJ and others hit tuning is cheap and easy. A big THANK YOU to AJ565 and Slipdog for sharing there experiances.
I cant thank yall enough riv187,aj565 and f150motocrosser for all the help and pointed me in the direction with advice i greatly appreciate it. I agree ive looked at lectrons and whenever i swap carbs on my dirt late model i always run into to something else with it.

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