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Costa Mesa, CA
US
Anyone have a baseline jetting specs for running a Keihin carb on the new KTM 250cc motor?
I'm running a stock engine with a pipe and around sea level and 100ll/91Oct mix, 50:1.
I heard the new 250 motor needs more fuel than the 2016 and older 250SX, FWIW.
I'm running a stock engine with a pipe and around sea level and 100ll/91Oct mix, 50:1.
I heard the new 250 motor needs more fuel than the 2016 and older 250SX, FWIW.
Anyone?
The Shop
I’m running a 185 main 48 pilot and the NE1i needle in the 2nd from the top at around 60-70 degrees seems pretty good but I feel the needle is too lean but I change the clip position and its definitely too rich I’m about 1000 feet. Curios if anybody had a better needle recommendation or jetting recommendation in general.
Sea level
Pro circuit system
Boyesen rad valve
38 pilot
Necj needle
3rd clip
165 main
more the the J starting diameter.
The 85 jet your referencing, I believe,is the starting jet, and shouldn’t be messed with.
22 MC 250 GasGas
36 mm PWK, 38 pilot/165 main/NECW #3 . Bike runs very clean, smooth (as smooth a 250 2 stroke can be !)
I have a flywheel weight, and with little patience found the sweet spot for the PV adjustment once I got the jettgin to my liking.
For some time I ran the TMX and used AJ's spec and was able to go up to rather large main jet but does not feel the need with the Keihin
Next I hold the throttle a steady rpms above idle , while opening/closing the screw to find the highest rpm point.
I'm about 1 3/4 now .
As far as the gas leaking out when tipped over, make sure the float is set at between 7-8mm, also loop the the vent hose out of the float bowl, and hold the hose looped with a zip-ty. I do that on all of my bikes.
I use 16oz of oil to 5 gals of fuel for every bike I own, which is a 40:1 ratio. NEVER change the fuel : Oil ration to correct a jetting issue.
Thanks for that vote of confidence. I’m currently trying to jet a bike for the first time in my life and just bought manual stock jets and needle and each size either side.
I’ve set it up as per stock settings and am going to go from there. She ran nice in the garage but we will see when I open it up.
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