PCM 343 running rough

[Kris20v]

PCM 343 running rough under load.
Hey there, I took my Boat out for a run on the weekend. It was idling fine but when put under load it was running extremely rough even a slight knocking nose and stalling. No engine light on and all gauges are reading fine I took the boat home and gave it a full service . Plugs ,leads ,all filters oil and fuel , impeller . After all that the boat is still running rough Under load and really hard to start now
any help would be much appreciated

[mikemcclain8]

Not sure on your boat, but if there is a cap/rotor, have you changed them out?

[boatwakes]

Likley time to remove and clean your fuel injectors. There's a write up on it.