I will not be able to explain as detailed as Frank will....but will give you the basics and he can elaborate.
Your motor, as you may or may not know, has a Fuel Saver Arrangement. It allows you to run at wide open throttle, with full spark advance, yet it slightly closes the throttle butterfly, to limit the amount of fuel/air mix allowed into the powerhead. So, you get ABOUT the same performance, with less fuel use. To use, just advance the throttle to full, then when on plane, back off a touch.
That being said, I think that perhaps the collar, on the fuel saver linkage, may have become dislodged? You can just barely see the fuel saver linkage in your pic, it runs horizontal out of the screen shot, towards the rear aft of the motor.
To set it, shift your motor into forward gear, and set the throttle to FAST.
Now you must ensure that you get full spark advance. The armature plate bracket where your plug wires come out of, MUST get stopped, and touch the crankcase boss, or stop. Push the armature plate bracket against the boss.
Now take that collar I mentioned on the linkage, and slide it aft, or back, until it touches the pivot pin. When it does tighten the lock screw.
Now you need to adjust your linc n sync, or the synchronization of the carb and the spark setting.
Loosen the anchor screw, which is below the linkage bar that runs between the roller and the carb.
Turn the throttle until the hash mark on your brass cam, that the roller rides on, is aligned with the pointer which is cast right into the crankcase.
Now get a flat standard screw driver, and turn the nylon eccentric left or right, until the throttle plate just cracks open.
Now retighten that anchor screw.
You should now be good to get to the water, to fine tune the needles.
I know this was a lot, but if you post a wider pic of your motor, I can show you items discussed so you can visually see what we are saying.
