97 Yamaha 40EJRW Jet. How to determine actual horsepower at head

[Bbaker24]

I have a 97 Yamaha 40EJRW (is what is on tag) I need to know the horsepower at the motor. I have looked everywhere. They say it’s a 30% decrease in horsepower. Not sure if this is at the motor (so I can order parts for) a 40, 50 or 60. It is a 3 cylinder 2 stroke. Tag on top of head says 820315

 

[Neutron]

Its a 40hp engine so you order for that. A simple google search found the info in seconds.