As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A PRE TAKE OFF IDLE CHECK THE ENGINE RAN VERY SLOW AND EVENTUALLY QUIT. THE INJECTOR SERVO WAS INSPECTED AND THE INTERNAL IDLE MIXTURE PLATE WAS FOUND TO BE SCORED. THERE IS A PROCEDURE FOR LAPPING THIS VALVE. IT WAS ACCOMPLISHED AND THE IDLE SPEED/MIXTURE WAS ADJUSTED.