Weird throttle issue- need your opinion

After taking my boat out on the boat this weekend, I have experienced some throttle problems that I need your opinion on.

Symptoms of Verado 150

  1. RPM’s and engine are ok if you slowly move speed up to plane(–3500 RPM).
  2. If you go from neutral to WOT, engine sounds very sluggish, and only goes to 4200 RPM. After about 5 to 6 minutes, RPM slowly move to 5000, and shortly thereafter it goes to 6250 RPM and runs fine.

What I have done before the problem:

  1. Boat had 300 hr service in late April
  2. Ran boat after service 4 times without filling it back up (approx. 14 gals. used)
  3. Added 2 cans of SeaFoam
  4. Drained gas out of fuel filter canister.

The boat has never given this problem before. It is also smoking (not exhaust) and vibrating more. Is this a bad fuel, injector, fuel pump, or supercharger issue?

Sandlapper1977

boat out on the lake that is…