Yamaha 225 four stroke losing power

[thomasg66]

I have 2003 twin 225 four strokes.The port side motor runs and idles fine, at any unspecified idling or under power the motor starts sputtering and almost choking itself to the point that it stalls. once I restart the motor it runs fine again for an unspecified amount of time. This very frustrating because there are no warning signs, the motor can run fine all day or it can run rough right out of the dock. Put new plugs in,changed the fuel filters including vst. Any suggestions would be appreciated.

[99yam40]

monitoring fuel pressures while problem shows up will tell is you are having problems on fuel system
I would think hooking it up to a laptop would give some info if the motors are set up for it

[Sequoiha]

this engine is known for the electric lift pump to fail, and this sounds like what is happening, it is mounted outside and infront of the vst on the port side.. could be getting hot and locking up,

[thomasg66]

Thanks for the info that is one thing i haven't looked at yet, i'll get back to you with results.