OX66 Low oil Alarm

[Mikviy58]

Was 70 miles offshore and the low level oil alarm on my 250 OX-66 went off. The motor went into limp mode and I shut it off. Main oil tank was full. One bar flashing on the Tach, indicating low oil. Oil in the on-motor tank was at low mark and wouldn't fill using the switch. Motor would run at low speeds and show full oil tank, but would show low oil and shut down if the throttle was opened.

Suspect clog somewhere in the oil line or a bad pump. Anyone have ideas?

[rodbolt17]

most likely that well maintained filter at the remote tank outlet is clogged.
what happens is the engine can consume oil faster than it can transfer at high speeds.

that's why after a few min idling the engine tank filled enough to stop the alarm but after about 1/4 mile at speed the alarm came on again.

with the key on had you held the switch long enough it would have filled.

[boscoe99]

For future discussions, note that the main oil tank is the engine mounted tank. The boat mounted oil tank is the remote tank or auxiliary tank.

It is the main/engine mounted oil tank being low on oil that causes the alarm to sound and the engine to go into RPM reduction mode. One bar flashing on the tachometer indicates that the main/engine mounted oil tank is low on oil. See diagram below from your owner's manual.

I second checking the oil strainer first. When was the last time it was replaced? If the filter in new, or gets replaced but the problem persists, then check the oil pump itself. Then, possibly the inside of the oil tank or the oil lines themselves. Stuff has been known to clog the system which slows down or prevents the transfer of oil from the remote/boat mounted oil tank to the main/engine mounted oil tank.