Yamaha F300 Surging

[deafbykhorns]

Still banging my head on this one, its been going on for 8 months now.
I have checked fuel pressure, changed filters, changed plugs, and can't figure out whats going on.
I also ran some of the YDS tests and tested OCV valves, ISC,TPS. OCV Filters have all been changed.
This is also an intermittent problem that seems to come about after it warms up.
I get an occasional stall while idling in gear as well. It runs fine other than the surging (slight up/down increase in rpm).
Fuel pressure on the rails is around 38psi when running and sometimes will vary a couple PSI.
It surges at higher RPM around 2800 and occasionally at 1100 rpm. Out of gear, they don't seem to run at same RPM with the same output from shifters.
Nothing unusual about the YDS readings that I can tell. I threw a code last month when changing batteries but its resolved now.

The drop box files are various videos of fuel pressure, YDS readings while surging, at different RPMs
Also attached YDS readings at idle and approx 1800rpm of both motors, the starboard is the one giving me trouble

https://www.dropbox.com/sh/1tmcltyfx...Ak37eGvra?dl=0

[Keithbaja]

Check and tighten all fuel line connections above and under deck. Also anti siphon check valve at tank output can/will do this. A good trick is to install a clear hose fuel line before motor and watch for air/bubbles

[deafbykhorns]

I put the clear hose on it this morning, no bubbles whatsoever. I put those check valves on it years ago..
I don’t think this is fuel related(between tank and injectors). At 2500rpm on port, starboard is only 1200rpm, this is out of gear! TPS and throttle input data looks fine on YDS. With motors in gear, they sync almost perfectly, this may or may not be unrelated to the surging.

[deafbykhorns]

Pulled injectors this afternoon and used injector cleaner to soak them.
15 min later I put injectors back in fuel rail and mixed in some cleaner. Fired up the air compressor and set regulator at 50psi. I connected12v power supply and fired them off one at a time and cycled several times.
reassembled and reinstalled, fired up engine and so far no surging. Not 100% confident until I water test it.
engine seems like it does idle better….