If it starts up fine and dies when you throttle up, try squeezing the primer bulb just before and while you throttle up. If that makes a difference, then you may have a bad fuel pump diaphragm, or some type of fuel delivery issue..
Do the spark test and a compression test.
Then check the fuel pump diaphragm.
Water in the tank?
Check the hoses.
outboardignition.com has test procedures for that motor.
No high speed could be a stator problem.