You don't need a mod, you need to fix your broken bike.

The 2009 KLX starts in any gear, so long as you pull in the clutch. Starts in neutral without the clutch pulled in.

You've got a component failure and I'm betting it is either the clutch switch or the kickstand switch.

 

Ok great! That is cake, I will check and mod tonight. Thank you for the write up and test procedures, maninthesea.

 

I just started having this issue on my '09 KLX250S. The fix for me was to tighten up the clutch cable as it had become a bit slack which meant that the clutch lever was not returning to the fully open position when I released it. When the clutch lever is open it should press the safety switch all the way in - that's required for the switch to reset itself.