My new to me pristine F4 1000S with only 3400 miles seems to start, idle and run very well. However, when pushing it a bit hard it will die on the shift from 1st to 2nd at anything above 8K RPM. It will not restart until I pull over and fiddle with the kill switch a few times. Otherwise I get nothing. It was as if I bumped the kill switch during the shift. So, I cleaned the kill switch with some contact cleaner, but it still does it. No other odd behavior. What do I look at next?