25 hp yamaha stall/stutter

[Speedaemonc4]

Thanks in advance for any help yall can give, new member here. I have an old 96 2 stroke yamaha outboard on my alumicraft and its been having some issues lately. Ive taken it to two different shops and hundreds of dollars later its still leaving me and my family stranded. It seems to be running a little rich, the carbs were rebuilt though. It will run fine for a while but after about 200 yards at full throttle it chokes and the motor starts shaking violently as it drops down to what one shop called a limp mode. Once this happens it will only run at idle smoothly. After waiting a few minutes you can once again go full throttle for about another couple hundred yards before it chokes again. The problem has seemed to get worse over time. I have a video of the issue that i will try to upload or if anybody would be willing to pm me an email address i can email the video there. Thanks again for the help!

 

[99yam40]

Is this a premix motor or oil injected?
Does this motor have an alarm system?
light, buzzer, or gauges with indicators?
good chance the motor is over heating or thinks the oil tank is low causing it to go into RPM reduction

 

[Speedaemonc4]

Is this a premix motor or oil injected?
Does this motor have an alarm system?
light, buzzer, or gauges with indicators?
good chance the motor is over heating or thinks the oil tank is low causing it to go into RPM reduction

It is oil injected with an alarm, it seems it will choke when it isnt even hot yet though, what would you say the solution would be? The alarm isnt going off either

 

[99yam40]

have you tested the alarm system lately to make sure it functions ?
testing to be sure is the best way to eliminate those 2 things as the cause of the RPM reduction

might use a timing light or spark tester to see if spark is being dropped on certain cylinders when this happens.
timing light would also show if timing is being affected.

could be running out of fuel at high RPMs.
check test fuel pump and look for sucking air into the system

 

[Speedaemonc4]

Awesome ill try that, thanks