I second what heagachongoose has said, check battery connection, voltage, load test if you have the ability. Look for corrosion on terminals and inside the right handlebar control.
If the right side run/kill switch is constructed like the left high/low beam switch it is possible you are not making contact when the switch is in the run position. I had the same issue with my high/low beam switch after modifying the wiring. There are copper contacts on two pieces and if they are not making contact no high beam in my case, possibly no run in your case.
To reiterate, more symptoms would help generate more specific things the check or try.