I have a E150GLERV 150 intruder, 1994, and today this happened.

Went fishing, ran out to my spot, maybe ten minutes @ 4500-5000, shut down, fished for two hours, cranked up, idled for about five minutes in gear (temp showed ok, no problem), got on plane, ran slow (it was dark) back to the ramp about 3000 rpm, came off plane, idled about 3-4 four minutes to dock, tied up, shut engine down.

I backed my trailer in, and when I got back into the boat to drive on the trailer, the solid tone sounded with the key on (no short -beep- for system check, just the tone).
I thought maybe it was hot, but it was showing 110 (my temp sender is on the left bank) so I thought maybe the right bank had a clogged thermostat. I started it let it idle for about 45 seconds with good water pressure, and alarm sounded conitnuously the entire time.

I don't have the system check guage, only the horn.

I've checked the oil level (good), the two temp sendors, even disconnected them with key on (engine off) and tone continues.

I was under the impression that the solid tone was overhead or fuel resitriction. I'm lost.