2012 ec300 running bad 1/4 to 1/2 throttle

[gas-gas 52]

Need some help on which way to go on jetting. I have a 2012 ec 300. It has a bog from 1/4 to 1/2 throttle. Elevation here is 800 to 2500 ft. Above sea level. Installed a J D jet kit, 180 main 40 pilot blue needle n the 3 clip, air screw 2 turns out. Still has a little bog in it but better than stock. Would like any help that anyone could give me. I also have a 2011 300 that I put the same kit in and ran perfect . Thanks

[gasgasman]

Try a new spark plug.
Fought this on my 2011 when it was new.

[gas-gas 52]

Will try that. Thanks

[GMP]

That needle and main run perfect in my 250s, surprised they are not rich in the 300. Slides the same? Try swapping carbs. From my experience when you start to get off the map with jetting in an attempt to cure a problem, something else is wrong.

[Jakobi]

Yep! Confirm both carbs are the same too. Swapping is a good way of isolating it and removing variables. Different model carbs have very different jetting requirements. If the 2012 has the AS2 38mm then I am not surprised that the jetting is off.

[gas-gas 52]

Thanks, that's a very good ideal.....will try it and get back to you

[Jakobi]

Might as well pull the reed block and check the petals while you're in there too. Its only a few extra bolts. If its low hours its unlikely they'll be damaged however I know of a couple bikes that managed to chip the lower rhs ones where they contact the cases.