Buy Yamaha Outboard Parts

Announcement

Collapse
No announcement yet.

OX66 250 (2003) power at low speed.

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • OX66 250 (2003) power at low speed.

    Have 250 hp OX 66 (2003) that has begun to shut down while idling. Runs fine on plane. No spit or sputter just dead stop. From battery to motor has been inspected and good to go. Motor restarts easily. Any ideas??

  • #2
    Does the motor ever run at idle or does it always shut off?

    Your model uses a two speed high pressure fuel pump. At idle (below 1500 RPM actually) it is in low speed pump mode. It is in high speed pump mode above 1500 RPM. Perhaps the circuitry that causes the low speed mode to function is inoperable.

    Pump a pressure gauge on the fuel injection rail. Monitor fuel pressure to see what happens when the RPM is retarded to 1500 or below. If you have fuel pressure above 1500 RPM and fuel pressure is lost when you retard the throttle to below 1500 RPM I would suspect the low speed pump circuit is faulty.

    Or simply inspect the resistor through which current flows to/from the fuel pump for any signs of distress. A blind hog stumbles upon an acorn every now and again. You might get lucky.

    Comment


    • #3
      Ox 66 250 hp

      Yes it will idle from ten minutes to 1hour. Then the motor cuts off abruptly. No spit or sputter. Just boom! Pump pressures check out ok. The thumb switch when pressed will slightly reduce rpm. But it has occured for 4-5 years with out any loss of power. Power loss has occurred in last 60 days. Motor will restart immediately. How would one isolate issue? Any ideas/

      Comment


      • #4
        does the fuel pressure stay in spec as it just shuts off?

        good chance there is no fuel to the cylinders if no pressure at that time

        Comment

        Working...
        X