I use this bike for single track/harescrambe/enduro. I know its a mx bike but ots all I've got. The problem is it overheats very quickly once in slow tecnical stuff. In our riding group there's KTM 250sx, KTM 450xcw, yz 250f, yz 450f and I am always the first or in most cases the only one whose bike is boiling and standing in steam. The bike is stock and has a 1.4 radiator cap. All suggestions welcome. Thanx

Start by making sure that the coolant level isn't too high.  The coolant level in a cold engine should be just above the rad fins.  I would also recommend switching to a 1.8 rad cap (stock on most '08 and newer bikes) and adding a coolant recovery system.  With the coolant recovery system, the rad reservoir can be completely topped up.

Thanks for the advice. I will change out the cap and look into the recovery systym

I would also recommend swappin the green fluid for the dexcool orange fluid. I found the green stuff eats at all the Alu parts and causes issues. The Orange coolant is Alu friendly. I would also get some DEI Rad relief and pour some of the bottle into your coolin system.

I ride in 20-30c weather and only change my fluid once every two yrs with no issues.

If you are changin from green to orange please be sure to flush your system properly...

I have similar overheat issue with a 2007 250SXF.  I have had a 1.8 cap on order from KTM for over a month.  I hope to get it within the next two weeks.

Have you been able to test the 1.8 cap to see if it resolves your issues?