I have a 1997 Bayliner Trophy 2509 with twin 1997 Mercury 150's (2-stroke and carbureted) with around 600 hours. A few weeks ago, I was cruising about 4000 rpm when the starboard engine just came down to about 1500 rpm and a rapid "beeping" alarm started. I shut it down and restarted it. The alarm continued. The engine would rev up in neutral, but would not go past about 13-1500 rpm under load without dying. I shut it down and came in on the port engine. Now the alarm will go off just cranking it over without actually starting the motor.
All my research says that alarm is an oil injection alarm. The engine reservoir is full, and the remote oil tank was ½-¾ full. I followed the troubleshooting steps in the service manual, but can seem to figure this out.
1. Faulty engine ignition system (incorrect voltage pulse being sent to warning module): I followed the green wire to the cylinder number 3 coil. I cranked it over (w/o starting) and got around 130-135 volts on my DVA. Not sure if it cranks at 400 rpm, but if it does that seems to be satisfactory.
2. Defective low oil sensor (located in fill cap of engine reservoir): I did remove the cap after disconnecting the wires to check it for cracks; none found. With the float in the full position there is NO continuity with the float in the low position, there is continuity. So this appears satisfactory. 3. Defective motion sensor at the oil injection pump: a. Step 1 was a little confusing. I had no voltage to the white wire from the module unless I turned the key on (the directions didn't say to have the key on or off, but it made sense to have it on). I only had around 10-11 volts which seems slightly low. b. Step 3 produced the required results of right at 5 volts and a drop to less than 1 volt every two revolutions. The sensor appears to be satisfactory. 4. Drive system of the oil injection pump. I haven't been able to complete this test yet. I need to get a remote fuel tank to run the engine. I did remove the oil pump and inspected it. O-rings and seals looked good. Pump spun freely. Drive gear looked good. No damage or deformities. And the coupler looked good. Magnet was still in place.
I am really stumped with this one. I would appreciate any and all advice/help. I am leaning towards a faulty warning module, but I don't see any way to specifically test it and I hate to buy a $250 part with just a guess. Thank you!!
All my research says that alarm is an oil injection alarm. The engine reservoir is full, and the remote oil tank was ½-¾ full. I followed the troubleshooting steps in the service manual, but can seem to figure this out.
1. Faulty engine ignition system (incorrect voltage pulse being sent to warning module): I followed the green wire to the cylinder number 3 coil. I cranked it over (w/o starting) and got around 130-135 volts on my DVA. Not sure if it cranks at 400 rpm, but if it does that seems to be satisfactory.
2. Defective low oil sensor (located in fill cap of engine reservoir): I did remove the cap after disconnecting the wires to check it for cracks; none found. With the float in the full position there is NO continuity with the float in the low position, there is continuity. So this appears satisfactory. 3. Defective motion sensor at the oil injection pump: a. Step 1 was a little confusing. I had no voltage to the white wire from the module unless I turned the key on (the directions didn't say to have the key on or off, but it made sense to have it on). I only had around 10-11 volts which seems slightly low. b. Step 3 produced the required results of right at 5 volts and a drop to less than 1 volt every two revolutions. The sensor appears to be satisfactory. 4. Drive system of the oil injection pump. I haven't been able to complete this test yet. I need to get a remote fuel tank to run the engine. I did remove the oil pump and inspected it. O-rings and seals looked good. Pump spun freely. Drive gear looked good. No damage or deformities. And the coupler looked good. Magnet was still in place.
I am really stumped with this one. I would appreciate any and all advice/help. I am leaning towards a faulty warning module, but I don't see any way to specifically test it and I hate to buy a $250 part with just a guess. Thank you!!