Re: Oil sending 150HPDI Yamaha
Do this. Remove the plastic sump attached to the main oil tank. Drain the tank completely. Reinstall and zip tie the sump.
Turn the key to the ON position. Wait a bit. The pump should start running. Does it? The pump will run for three minutes or until the tank if full, whichever occurs first.
With the pump running oil should be flowing from the remote tank to the main tank. Does it?
The main tank sensor has three switches in it. Top switch (float up) grounds to tell the ECU to stop transferring oil. Middle switch (float in middle) grounds to tell the ECU to command the transfer of oil from the remote tank to the main tank. Bottom switch (float down) tells the ECU to put the engine into RPM reduction mode/turn on the horn/flash the oil bars on the tachometer.
If the remote tank is low on oil then when the main tank float goes to the middle position the ECU will not call for oil to be transferred. But, you should see this on the tachometer. Plus, you said the remote tank is full.