I have a 2003 Yamaha 150 2 stroke V6. When running around 2 - 3 MPH at low RPM's for about a minute or so my oil alarm starts sounding. The oil tank has plenty of oil. If I accelerate to get the RPM's up the motor starts to die out so I throttle back. After going through that about 6 - 8 times the alarm will stop and the engine will start running fine run fine. Like I said it only happens when in gear and idling real slow for a minute or so. I assume its the oil pump and it must be a mechanical pump. Any ideas?