Looking for some help...engine down on power

[aftershock]

Recently purchased an Aftershock 21 Skier with a 6.0 Vortec (Kodiak Marine) and a dominator setback pump with 260 hours. Last October while up north at Lake Don Pedro for a houseboating trip it ran good for 5 out our 7 day trip. Started it up on the 6th day and it would not rev past 3000rpm. Called Kodiak marine and they said it was in limp mode because of a fault code. Got my hands on a Rinda Techmate Pro but their are no fault codes. Changed the fuel filter but that did not help. Throttle cable and linkage is still working good. It revs to 5000rpm on the trailer if I blip the throttle so for some reason it wont rev under a load. Any ideas of where to go next? I'm thinking the pump, but it doesn't vibrate nearly as bad as I would think it would if the pump was the issue, but maybe I'm wrong?

 

[Done-it-again]

Not a pump guy. But have you cleaned out the filter for pump. Not sure what it’s called. My neighbor had clogged his up from beaching and sucking up rocks etc, and it wouldn't run. Was towed in and sent to the dealer only to tell him he sucked rocks/ sand then charged him a grand to clean it out.

 

[Melloyellovector]

Check pump intake, or impeller could be loaded with debris

 

[Shlbyntro]

Check/replace spark plugs. They could be fouled from 5 days of hard use. Take notice of any inconsistencies on the plugs as it could be indicative of an ignition system issue such as a bad coil or plug wire which does not always register a code. Low/high fuel pressure and/or fuel quality can cause running issues and not throw a code also, maybe you got bad gas somewhere?

Always start with the simplest items and work your way from there.

(I always pull a compression test when I change spark plugs, pb&j)

Good luck