2015 KTM 250 Jetting

K22
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K22
Edited Date/Time 4/7/2015 3:56pm
Hey Guys,

I have a 2015 KTM 250 with a 38mm pwm carb installed. Currently have a 172 main and a 40 pilot and running 50/50 avgas. Weather conditions here are starting to cool but top temp is about 33 degrees Celsius. I have been having a bit of trouble tuning my carby, it seems as though it is spluttering through the mid section, you have to either be on full gas or nothing. Wondering weather i may need to reduce the main jet to get a better roll on with the power or whats the best option. Cheers.
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swedishfishmx
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swedishfishmx 4/6/2015 9:54pm
4/6/2015 9:54pm
33C is pretty warm if not hot. Spluttering or whatever you call it in the mid-section is most likely the needle. I'm assuming your spluttering is is most likely a rich condition, because if you were lean the bike would ping and run flat. Try going up one position on your needle to lean the system out.
KTMShane699
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KTMShane699 4/7/2015 6:47am
4/7/2015 6:47am
What needle are you using? The 172 main is even a bit lean. I ran a 175 main and a 42 pilot with a NECJ needle out of a Suzuki. I used this setup all summer last year and it ran great.

Shane
K22
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K22 4/7/2015 3:56pm
4/7/2015 3:56pm
Hey shane, im running the same as you, NECJ out of a suzuki. I am getting a bit of splooge out of the header pipe so it is definitely more rich then lean, I guess it will just be a matter of trial and error.

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