It's not a vacuum leak. If it had a vacuum leak it would be difficult to keep it idling. This is what I would do. Run the boat up til it starts to stumble. When it starts to stumble vigorously pump the throttle. You have to do it very quickly. What this will do is keep activating the accelerator pump. If the stumble quickly goes away (faster than normal) you will know that you have a lean condition in the carb causing your stumble. I would do this and see what happens because you very well could have an ignition issue.

Black Baja... I was doing something similar the other day and it actually caused the motor to back fire.... That and it really only does it if you are initially on the throttle quickly. If you ease into it, it barely does it...

That said Ill try to give it a shot next time im there...

I've had many vehicles with vacuum leaks that had no trouble idling. Sometimes a little high, or a lot high , depending on the leak.

Every engine has a vacuum leak

a large vacuum leak can cause the engine to die at idle.a small vacuum leak will increase the idle speed.

Mine seems to idle quite well.... nothing can ever be simple... lol

I didn't read that it idles ok. Never mind my post lol.

two things that are probably common here. Throttle position. In nuetral, at 2500-3000RPM, you are just off the idle circuits. IN GEAR, just above idle, you are just off the idle circuits.

The idle circuit still plays a part in the transition until the main circuit becomes active. If the idle circuit is too lean, you can get a chitty transition, or "dead" spot. I've seen guys tune carbs on boats for the cleanest idle in nuetral, by turning the mixture screws in too far. Then, as they are trying to get on plane, the engine coughs back thru the carb. in these scenerios, backing the idle mixture screws out to enrich the idle circuit, solved the "lean sneeze" problems they had.

you may need an acc pump cam that starts the shot earlier.

Damn... might be my issue MILD THUNDER. I had adjusted the 4 corner idle screws after going for that first ride... I turned them in a 1/4 turn each BC it seemed to he running a lil rich... that said after I ran into this hesitation I turned them 1/4 back out... maybe I'll try going out some more

It really sounds to me like you have an ignition issue.