oil alarm went off on 2 stroke

cool change

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hello all, had a question when i was coming in today with my 1998 yamaha XO66 2 stroke my oil alarm went off i lost power and limped back to the dock. I had plenty of oil in my main resevoir tank and also the small resevoir on the motor showed half full. I am hoping it is not a serious problem. Any help as always would be appreciated thank u
 

seasick

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cool change said:
hello all, had a question when i was coming in today with my 1998 yamaha XO66 2 stroke my oil alarm went off i lost power and limped back to the dock. I had plenty of oil in my main resevoir tank and also the small resevoir on the motor showed half full. I am hoping it is not a serious problem. Any help as always would be appreciated thank u
First question: Are you sure it was an oil alarm and not an overheating alarm?

let's assume it was an oil alarm. The limp mode will only happen when the engine mounted tank (the main tank) is sensed to be at the low end of the sensor range. The sensor or float switch has three positions, full, halfish and low. If the oil level goes below the low level, the motor will switch into limp mode.
The tank could be low or the sensor could be sending an incorrect signal.That is easy to test bu pulling the float sensor out, holding it erect and sliding the ring float while watching the oil display.

Often times, what happens is that the oil use is greater than the oil delivery rate. When that happens the main tanks empties. When you go slow, the fill rate may be sufficient to keep the tank at the current level or actually fill it. By the time you limp back and get the cowling off, that main tank may be filled above the alarm level. The reasons for low delivery rates to the tank are usually a clogged screen or bad oil pump and sometimes gunk in the remote tank. To clean or remove the remote tank screen (filter) the tank has to be removed. The filter is on the back side.

There is a manual oil fill switch on the motor (a toggle switch) that when flipped will cause the remote tank pump to run. If the main tank is somewhat low, you can see how long it takes to fill the main tank when the switch is used. It shouldn't take a long time. There is a more scientific method that requires you to undo the oil feed line and measure how long it takes to pump a specific amount of oil. I don't remember the spec at the moment.

If you want to diagnose further, run until the motor goes into limp mode and immediately shut it off. Remove the cowling and verify that the main tank is low. Turn on the ignition and confirm that the remote pump is operating and see how long it takes to fill the main tank.
Let us know how you make out.
 

glacierbaze

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Good info, Seasick. Most of us would probably refer to the big reservoir as the 'main tank'. When it goes into limp mode, shouldn't the pump fill the main tank? And when/if it does, does the motor resume normal operation, or is there a reset process?
 

cool change

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thanks seasick.. here is what i got.. i am pretty sure it was the oil because on the yamaha gauge the oil light was flashing, and also the pee stream was still strong. when i limped back to the dock the arlarm was going off and on with little power [about 1000 rpms] when i docked i pulled the cowling and noticed the main tank on the motor was about a quarter full so i push up the toggle switch and it slowly fill up thats all i did.. do u think it was a overheating problem or oil ? I was thinking a oil sensor if it was the oil . If it is any of the things u mentioned is it a costly fix ? as always thank u
 

seasick

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cool change said:
thanks seasick.. here is what i got.. i am pretty sure it was the oil because on the yamaha gauge the oil light was flashing, and also the pee stream was still strong. when i limped back to the dock the arlarm was going off and on with little power [about 1000 rpms] when i docked i pulled the cowling and noticed the main tank on the motor was about a quarter full so i push up the toggle switch and it slowly fill up thats all i did.. do u think it was a overheating problem or oil ? I was thinking a oil sensor if it was the oil . If it is any of the things u mentioned is it a costly fix ? as always thank u
Good info to start.
At a quarter level, the main tank would probably signal a LOW condition and that will cause the limp mode. I am not 100% sure but I suspect that if the alarm is cleared, the motor will switch back to normal mode.
You say that you used the override to slowly fill the tank. So the question now is weather the fill rate is slow or something else. The more common cause for a slow fill is a blockage, sludge or clogged screen/filter but is could be a signalling issue or a bad but not completely dead oil tank pump. It is simpler although a bit of work to remove the tank, pour out the oil, check for sludge and replace (or clean) the inline filter.
Of course, you can pull the oil feed off of the main tank andcheck the flow.
There are other possible causes for your alarm but they are more complex to diagnose. An important test is to see if the pump on the remote tank is running when the main tank is low. You said it runs when you use the override but does it run at all in normal operation? I am not sure how you motor handles the refill logic but some models need the motor running for the main tank to refill. Of course with the motor running it is tough to hear the pump so one way to see is to remove the main tank sensor and with the motor running, make sure the sensor is straight up with the 'float' slide down. That should both signal an alarm and signal the remote pump to operate. The main tank should fill up. You don't have to drain the main tank, just watch out that you don't overflow.
While you are at it, slide the float ring up top and let us know if the alarm clears:)

I tried to do a really rough calculation of how long the motor will run on only the oil in the main tank. That tank holds about a quart of oil and a quart of oil will handle 12.5 to 25 gals of gas depending on the mix ratio which varies by revs, but lets use the 50:1 ratio.
At cruise my motor burns about 12 gph so a quart of oil will run for an hour or thereabouts assuming that the remote tank is not refilling the main tank at all.
 

DennisG01

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That's a great write-up, Seasick. I think the notion of checking the filter screen on the remote tank (FYI, that is correct... the boat mounted tank is the remote, while the engine mounted tank is the main tank) is a great first step. Gear oil sometimes tends to get sludgy over time and the tank should really be cleaned out every so often. While this may not be the issue, it's very possible that the filter screen was clogged up just enough to not allow full transfer of oil. So, at higher RPM's it wasn't able to keep up and the main tank got low. At lower RPM's, there was enough oil being transferred to keep the alarm off.

Not for nothing, but considering the nature of your question, Cool, I'm going to assume that you have never cleaned out that filter on the remote tank? I would at least start with that since that is something that should be done, anyways. HOPEFULLY that also solves the issue for you!
 

TUNAHUNTER197

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Check your remote tank's wiring harness for corrosion. Since that harness lives in the bilge it's susceptible to corrosion. I have since cut the harness and hardwired everything with waterproof butt connectors and heat shrink.
 

seasick

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TUNAHUNTER197 said:
Check your remote tank's wiring harness for corrosion. Since that harness lives in the bilge it's susceptible to corrosion. I have since cut the harness and hardwired everything with waterproof butt connectors and heat shrink.
I have heard of several instances where the wiring broke in the harness where it goes through the grommet. I would have to look at the rigging diagrams but I think that if the wire breaks, the override fill switch doesn't work either. Since the fill switch did refill the tank, I skipped over the broken/corroded wires possibility for the time being.
For those who may be new at troubleshooting Yami wiring, it is important to note that many signals for devices like the remote oil pump, work by switching the ground signal on and off. The +12 volt signal is on all the time as long as the ignition is on. The point is that one might look for 12 volts, see it and assume that the signals are correct and that may not be the case.
 

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I have heard that mixing different oils, particularly petroleum and synthetics, can sometimes cause the mix to gel and block up the system. But isn't that what a 'synthetic blend' is anyway?
 

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Had same problem Ox66 225hp. Blinking oil alarm.
FYI, next time you can pour oil directly into the "main" small tank on motor and relax and get home or keep fishing...

Pump was not working. looked a little rusty. took it apart to see. tried to clean out rust spot inside. magnets were loose inside, supposed to be glued in place.
replaced pump and strainer.

Boats.net
6E5-81900-01-00 MOTOR PUMP ASSY (Yamaha Motor) $155.
10646-24251-02-00 STRAINER 1 (Yamaha Motor) $13.52

worked great. ran 220 gals of gas without a problem.

had to add more to remote tank, nearly empty, Used Pennzoil instead of Yamalube to try it $20 vs $50.
Got error after running a while, small tank was half filled. Not sure why, maybe stirred up junk or airlock from being near empty?
Piddled around with tank it started filling, dunno what fixed it. Might need to get drained and cleaned out.
 

cool change

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ok guys here is what I got , oil pump is working, drained tank and replaced screen although it seemed clean went on a test ride alarm went off again went into limp mode and lost power. limped home was holding off buying oil sensor at a 168 bucks but I did installed it took her out for about a 1/2 run ,no arlarm and main tank on motoris reading full.