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oil sensor testing 150 Vmax

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  • oil sensor testing 150 Vmax

    I have '98 150 Vmax with oil tank problems. The engine reservoir levels continue to drop. The oil pump does operate when the switch is raised, but not in normal operation.

    Is there a way to test the oil level sensor in the engine oil tank?


  • #2
    If you Yamaha gauges with the oil level lights then look to see which level it's indicating.
    Green light or full and no oil transfer means a problem with engine oil tank sensor or oil control module((if pump works ok with toggle switch).
    Yellow light or middle indicator with remote oil tank in boat low on oil then add oil to see if low oil light goes to full. Oil transfer pump will not pump oil to engine tank if remote tank is low on oil.
    Yellow light and remote oil tank full then check oil level sensor and wire harness in remote tank.
    Yamaha Outboard Parts


    • #3
      I have a 1994 Pro V 150 with the same problem. Your wire colors may not be the same however there is a way to bypass the magnetic oil level sensor in the main oil tank (the one on the motor), for the purposes of testing. There should be wires coming out of the oil tank. Follow the harness down to the first connector you find and and pull it apart. There should be four wires. On the end that goes up to your control unit (the black box or CDI), on mine I was instructed to jump the Blue/Green wire with the Black wire. (again your wire colors may be different) The oil pump in the remote tank should come on and stay on. Then jump the White wire with the Black wire and the pump should shut off.

      If it does all this then your oil sensor in the main tank is bad, however if it does not do this, as in my case then either your wiring is bad or you have a bad CDI unit which is expensive. Of course, this is what I need.

      I got this info from the Seloc Manual.


      • #4
        Oh sorry I just saw the date on your post. You probably have it fixed already. What did you find?


        • #5
          I am trying to diagnose a similar problem. I have a 1987 v6 150 hp. My red engine light was coming on but no audible alarms. New water pump, impellar and thromostats checked out. Oil reservoir on engine was real low but would not fill. When I filled it with oil manually, red light went out. Is this an electrical issue or maybe a problem with the oil tank pump or filter? What should I do to fix.


          • #6


            • #7
              Possible sensor issue?

              I have a ‘99 yamaha vmax 150 2 stroke fuel injected auto oil mix. I recently had an issue where I was cruising around 3200 rpms and the engine buzzer would go off and degrade the engine. It happened twice the first day and then the second day ,after an hour of running normal, it wouldn’t let me get above idle or the engine would degrade. I had to get get back to the dock on trolling motor in the dark, not fun. After inspection in the day light, I found that the oil reservoir under the cowling was low and not refilling from the hatch oil tank. Using the emergency fill switch on the back of the power head, I found that the pump was running on the hatch tank but still not filling. Come to find out, the small inline oil filter on the oil line from the hatch tank was completely clogged. $16.95 and it was fixed, so I thought... I took the boat back on the water to run it and it will run great for about an hour, then the buzzer will go off and the engine will degrade. After I pull it back to idle for 5 min then the buzzer will go off and I can continue to run normally until the next time the buzzer decides to go off (about 30min- hour). That filter was definitely one problem idk if this is related or another issue. I immediately checked the cowling oil reservoir and the oil level was full unlike the last time. I have replaced the water pump, thermostates in the last 2 months. I have a temperature gauge and a water pressure gauge which both look great when running the 3200 rpm. Low temp and 25psi pressure. Only thing I can think of is a faulty reading from a temp sensor that’s sending me a false temp on the gauge? Or a faulty oil level sensor? Any ideas? Any help would be much appreciated. Thanks guys