HELP! Can't get over 3800 RPMS yamaha pro saltwater series 150 hp 1990 two stroke

[jofjds2011]

Hi, please help. We have a 1990 grady white gulfstram with twin 1990 150 hp V6 yamaha pro salt water series engines. The starboard engine reaches 4800-5000 rpms with more power available. The port side engine will not go over 3800 rpms with WOT. The boat gets on plane easily and runs great. Once you try WOT the port engine hits 3800 rpms and backs off 300-400 rpms on its own. Other than this issue both engines seem great. Turn right over, do not run rough or smoke excessively.
Things we have checked:
Compression- all ok about 100 psi or above on all 6 cylinders.
Spark plugs- ran motor pulled each spark plug, dropped rpms on each cylinder
Swapped oil tank sensor on engines- no change
Swapped thermal coupler- no change
Oil injector button working
Oil reservoir fills appropriately
Checked carburetors- open fully, and very clean
Throttle cable- ok
Throttle linkage- ok
At idle both motors run about 6-7000 rpms
At cruising speed both motors maintain RPMS, but the throttle controls need to be at different positions the port motor needs to be forward about a inch further than starboard control to keep running at same RPMS
Problem occurs with WOT attempting to get passed 3800 rpms
Sprayed ether into carbs while running- no change
Two new fuel water seperators
We put fuel stabilizer when we fill the gas
oil tanks are filled


Any help would be amazing, please and thank you.
Jennifer

[rodbolt17]

fix the fuel system, test the alarm, quit swapping sheet.

[walleye1]

You have carbs running out of fuel, check fuel pumps for leaks. no leaks disassemble and clean the carbs.

[panasonic]

As Walleye said above. Try pumping the primer bulb when it is happening and see if it picks up rpm.

[amahaork]

pick up tube inside tank clog

[99yam40]

pick up tube inside tank clog

primer bulb would go flat in that scenario