Welcome to the board.
When I first got my 851 it kept conking-out on me due to the battery being drained all the time. We fitted a 916 regulator and since then it's been fine.
Another good tip I was given, which ties in with the advice given by weeveetwin is don't stall it. If you do turn the key to off wait a second and then start it up again. The computer needs to reset itself. If you don't do this it could start backfiring and running like bag of S'!t.
Happy riding
