Steve if you take it to advanced auto & have it scanned they can tell you what you need to fix the ABS. At that point you can do the brake check in gravel to get the air out.
Dave
Steve is the ABS light on ? if so the pump won't run. If not did you say you did run 1 front tire on gravel & hit the brakes. You don't have to be going that fast.
Dave
Blaxmax that should only happen if in gear. Other then that it should start up. I had a kickstand switch relay go bad & everything worked fine except no spark.
Blaxmax
If it's just popping out of 2nd & as long as you just shift it in a normal way I'd say you'd get tiered of riding the bike like that then before you had a problem.
Dave
You need to look at the shifting lugs & the pockets they insert in. The leading edge should look like new on both. If they are shiny & rounded off they should be replaced.