BIG jetting changes 2019 KTM 250sx

opyguy
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opyguy
FYI
Pilot goes to 35 from 42.5
Main goes to 450 from 440
Needle goes wayyyy rich, 6BFY42-71 from 43-73
needle jet stays same S-1

just an fyi
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BR8ES
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BR8ES 6/5/2018 8:26am
6/5/2018 8:26am
Hopefully it works
AJ565
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AJ565 6/5/2018 9:01am
6/5/2018 9:01am
The slide made the biggest change on my bike, I wonder if that changed too.
1
sandman768
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sandman768 6/5/2018 10:20am
6/5/2018 10:20am
Those are steps in the right direction, the 17 &18"s which share the same jetting, are too rich on the pilot & too lean on top...
honda70
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honda70 6/5/2018 4:39pm
6/5/2018 4:39pm
43-71 lean needle 43-73 rich needle ?

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opyguy
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opyguy 6/5/2018 4:47pm
6/5/2018 4:47pm
43-71 is richer
Second number is the diameter
opyguy
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opyguy 6/5/2018 5:13pm
6/5/2018 5:13pm
Only missing ingredient is the slide, manual doesn’t specify
Needed info should be in your manual in the tuning engine chapter , good chart of rich to lean needles
sdhuskyrider
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sdhuskyrider 6/19/2018 11:10am
6/19/2018 11:10am
Nice! Further validates all the changes that we collectively made on the 17's and 18's. I dont get how you develop a new bike and not spend a few days getting the jetting sorted out before delivery. Blows my mind.
JohnMatrix
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JohnMatrix 5/18/2019 8:56am
5/18/2019 8:56am
Bumping this. Has anyone here had any luck determining which jetting, needle, slide mods that the 19 responds to well? Same as the 17-18? Thanks!
AJ565
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AJ565 5/18/2019 5:00pm
5/18/2019 5:00pm
JohnMatrix wrote:
Bumping this. Has anyone here had any luck determining which jetting, needle, slide mods that the 19 responds to well? Same as the 17-18? Thanks!
Same as the 17-18’s.
AJ565
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AJ565 5/20/2019 6:48am
5/20/2019 6:48am
Slosh 112 wrote:
what pre mix ratio you guys running?
With T2 mixed 40:1 or u4.4 mixed 44:1 with amsoil dominator
MJ 490
PJ 37.5 (when cooler out, below 65*) 35 when above 65*
AS 2.0 turns out
NJ S-4
Needle 42-75 3rd clip
Slide 5.75
PV 1.75 turns in


With C12.
MJ 460
PJ 32.5
AS 2.0 turns out
NJ S-4
Needle 42-75 3rd clip
Slide 5.75
PV 1.75 turns in
Straight C12 mixed 60:1 with amsoil dominator
1
Dannyderasmo106 7/2/2020 3:37pm
7/2/2020 3:37pm
Anyone have any jetting specs for the 2019 250 sx yet? Ive been riding it bone stock and it wasnt bad but today was the first hot day of the year here in ny, 92 and humid, and the bike was pretty lean. Looking for some tips for a warmer weather setup.
sandman768
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sandman768 7/2/2020 4:30pm
7/2/2020 4:30pm
Dannyderasmo106 wrote:
Anyone have any jetting specs for the 2019 250 sx yet? Ive been riding it bone stock and it wasnt bad but today was the first...
Anyone have any jetting specs for the 2019 250 sx yet? Ive been riding it bone stock and it wasnt bad but today was the first hot day of the year here in ny, 92 and humid, and the bike was pretty lean. Looking for some tips for a warmer weather setup.
Hot & humid conditions should make your jetting richer not leaner...
3
JohnMatrix
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JohnMatrix 7/2/2020 5:16pm
7/2/2020 5:16pm
My current setup is 5.75 slide, S-1 needle jet (stock), 17-62 needle (suzuki needle) and 35 pilot (stock) and 450 main (stock) with a bills system. Bike has been running really well in all California weather conditions. Tried a 40 pilot and it was too rich. I'm about 1.5 turns out on the air screw.
AJ565
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AJ565 7/2/2020 6:58pm
7/2/2020 6:58pm
Dannyderasmo106 wrote:
Anyone have any jetting specs for the 2019 250 sx yet? Ive been riding it bone stock and it wasnt bad but today was the first...
Anyone have any jetting specs for the 2019 250 sx yet? Ive been riding it bone stock and it wasnt bad but today was the first hot day of the year here in ny, 92 and humid, and the bike was pretty lean. Looking for some tips for a warmer weather setup.
https://m.vitalmx.com/forums/Tech-Help-Race-Shop,42/KTM-HUS-125-150-250…

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