Yamaha F225 Dropping RPM intermittently

2007 F225's. The starboard one just started dropping RPM's 200-300 intermittently while on plane. Drops for a few seconds then back to normal then repeats 20-30 seconds later. Also hesitant sometimes throttling up to get on plane and may only get to 5200-5400 RPM full throttle. Most of the rest of the time it runs perfectly well and achieves full throttle. Port motor runs fine so not fuel issue. Just had oil serviced, fuel filter changed and injectors cleaned (problem occurred before and after service so not correlated). VST filter changed out past winter.
Any thoughts?
Failing high pressure fuel pump?
Thanks

I would look at the fuel pump driver. I don't know how to test it, but it's the only other electrical component aside from the low & high pressure electric pumps (and coupler connections in between, obviously). Seems like your fuel system should be pretty clean, given the recent service it's had.

More remote possibilities would be a bent needle valve in the VST not sealing properly or a sticky pressure regulator.

Edit: I suppose you could try swapping the fuel pump drivers, and see if the problem moves to the other engine.

Drain the VST, check for water( I know you said it's all new)?

Could be: bad plug, plug wire,coil going bad, stator, bad connection.

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