DF175 cuts out Cape Coral Florida

[asapmarty]

I have a 27 ft catamaran with 2 2006 DF175 Suzuki 4 stroke outboards.
The starboard engine cuts out intermittently at around 3000 RPM and then comes back on at about 2800 RPM. If I throttle down it will run fairly steady at 2800 RPM. Each motor has its own fuel tank. Since I have 2 of the same motors, I have been swapping suspect parts to see if problem moves to other motor. I have swapped plugs and coils, neutral switch, High Pressure fuel pumps, low pressure fuel filter, ECU. No luck. There are times when the problem goes away and the motors will both run great for hours. Then the cutting out will come back without warning. This makes the boat unreliable to go offshore and I never see any check engine lights. I have pulled the fuel pickup tubes out of the gas tanks and they look good. I have replaced the fuel hoses from the tanks to the water seperators, and from the seperators to the bulkhead fittings near the engines. I am starting to draw a blank on what could be causing this issue.
I always use marine 90 fuel. I keep the tanks full. I have swapped fuel hoses from 1 motor to the other and problem persists.
Suggestions would be appreciated.

[boats.net]

Sounds like a fuel issue, connect a fuel pressure gauge and monitor fuel pressure.

[asapmarty]

Wher would be the best place to connect to monitor fuel pressure?
What type of rig do i need?
I know that I cannot simulate the engine under load by hanging it in the water from my boat lift and reving it while it is in neutral.
The rev limiter will kick in at about 2800 RPM.
I could take off the prop and try it in gear but that would not be under load either.
If I rig up a pressure gauge to the engine and take it out on the water without the engine cover, the engine will get soaked as the spray off the back side of the boat hits the engine a little bit.
Any suggestions would be appreciated.
Thanks

[dcnguyen63]

infamous white wire

get its fuse holder cleaned and air-flushed out and fuse replaced.. see if it helps... I replaced everything. but nothing seems to clear.. now I am planning to replace the whole wiring harness from the batteries to the key switches this weekend..

[fintel]

df175 cuts out

replace primer bulbs,with good qaulity ones, and also get rid of anti siphon valves on fuel pickups, ethanol is causing all of this. worked for me on my 140 suz. good luck ,let me know

[pelermon]

Which neutral switch did you replace?
The one on the engine is the one you usually have problems with.