1999 yamaha ox66 no power

[Jennis74]

1999 225 hp efi,wont power up enough to even get on plane. It seems to be in
Return to port mode. The fuel is fresh and crystal clear, main filters just changed.I have twins on a 227 sailfish walkaround. Im thinking the Tps ??

[99yam40]

there is not such thing as a return to port mode.
there is a RPM reduction mode to warn you of a bad problem happens but your buzzer fails to notify you. if that happens you are not suppose to keep running the motor.
you need to shut it down and solve the problem it has.
it will limit RPM but not shut down, so you can get to a safe position out of traffic.
Run it too long and you may just kill it completely.

start with the basics
make sure your alarm system is functioning properly and that the gauges indicate as they should.
did you look at the gauges to see if they showed anything ?
did you hear a buzzer alarm come one?
test compression, spark, timing, and fuel pressures

[lswjth3@yahoo.com]

VST filter, pressure regulator filter, check for corrosion on the yellow and black wire under the ECU box, primer bulb, check fuel pressure, disconnect TPS sensor and see what happens, OX sensor, Check the stator coils for correct voltage and ohms, check the pulser coil for correct voltage and ohms.

[Jennis74]

Thanks much for info will let you know the results.