I have owned a 1997 Mariner 150 carburated model since 2002. It has relatively low hours, but I run it every month or so for a while and use it a dozen times or so each summer. Last time out, I had the oil alarm go off just after leaving the dock. I checked the oil resivoir and it was full. I restarted and the alarm did not sound. I ran it for about an hour and headed offshore.
10 miles out, it sounded again. I shut it off and restarted. It ran fine for 15-20 minutes and started again. Again, I shut down and waited a while while trying to figure it out. I called a mechanic and he said the oil pump gear could be shot, but he was perplexed that the alarm was intermittent. I had no extra oil to mix, so I headed back. After 6 miles at about 4000 rpm, it went off again. I waited about a minute and restarted. I barely got on plane before it went off again. I did notice that the cadence and sound level increased one step before I could get it shut off several times.
I waited a few more minutes and tried again. It made it another 12 miles or so with a lot of idling and moderate running (4000-4500). The alarm hasn't gone off again.
I played with the cap sensor wires and could not cause it to go off. The same with the motion sensor wires. The float alarm works fine.
I read alot about the oil pump gear being plastic. Tonight, I pulled the driven gear shaft and looked in the hole. I see the toothed gear to the left and it looks fine. It actually looks like it is metal. I did not see any debris or plastic in the shaft hole.
Could this gear actually be metal? Or, is the plastic gear that everyone talks about not visible from the outside of the engine? I have looked at just about every diagram in the parts manual and I can't find the disc shaped gear in it.
I don't have the meter to check the motion sensor, but it is obvious that the pump is oiling due to the smoke.
Could the gear stop turning intermittently without failing completely?
Any help would be appreciated. Thanks, Dan
10 miles out, it sounded again. I shut it off and restarted. It ran fine for 15-20 minutes and started again. Again, I shut down and waited a while while trying to figure it out. I called a mechanic and he said the oil pump gear could be shot, but he was perplexed that the alarm was intermittent. I had no extra oil to mix, so I headed back. After 6 miles at about 4000 rpm, it went off again. I waited about a minute and restarted. I barely got on plane before it went off again. I did notice that the cadence and sound level increased one step before I could get it shut off several times.
I waited a few more minutes and tried again. It made it another 12 miles or so with a lot of idling and moderate running (4000-4500). The alarm hasn't gone off again.
I played with the cap sensor wires and could not cause it to go off. The same with the motion sensor wires. The float alarm works fine.
I read alot about the oil pump gear being plastic. Tonight, I pulled the driven gear shaft and looked in the hole. I see the toothed gear to the left and it looks fine. It actually looks like it is metal. I did not see any debris or plastic in the shaft hole.
Could this gear actually be metal? Or, is the plastic gear that everyone talks about not visible from the outside of the engine? I have looked at just about every diagram in the parts manual and I can't find the disc shaped gear in it.
I don't have the meter to check the motion sensor, but it is obvious that the pump is oiling due to the smoke.
Could the gear stop turning intermittently without failing completely?
Any help would be appreciated. Thanks, Dan
