OX66 oil/temp alarm going off

The oil/temp alarm on one of my 2001 200 OX66's is going off, and I don't even know which one it is. I have the digital gauges, neither is showing high temp, and I'm getting a good water stream from each motor. It only happens at high rpm's, and draws an rpm reduction when the alarm sounds. If I throttle down and put it in neutral, the alarm stops. I just thought of how I could tell which one, by putting them in neutral one at a time Anyhow, I took the cowlings off, and the oil reservoirs on both stay close to the full mark the whole time, even on plane. How long would it take me to tear something up if I REALLY wasn't getting any oil? Anyone have any experience with this?

Re: OX66 oil/temp alarm going off

are you just hearing audible and not seeing anything flashing on the gauges??
that doesn't seem right.
there could be three things going on
1) overheat - single flashing indicate.
2) low oil - single flashing indicate
3) oil transfer - all indicates flash.

review pages 2-9 and 2-20 in your owners manual.

http://www.yamaha-motor.com/outboard/service/viewmanual.aspx?ls=outboard&yr=2001&lid=5&mid=720

Re: OX66 oil/temp alarm going off

I am with Abe.
RTFM
is it to hard to observe the gauges when it alarms?
low battery,overheat or low engine oil level are about all that will trigger an alarm while runinng on that engine.
there are NO oil flow alarms.
your digital gauge will tell you which alarm is occuring if you look.

Re: OX66 oil/temp alarm going off

Sorry fellas, failed to mention that the gauges indicate nothing unusual. Temp bars are not up, nothings flashing, tfm doesn't have a whole lot of info about troubleshooting this stuff...thanks for the info! I'll take a pic of the gauges today when the alarm goes off...

Re: OX66 oil/temp alarm going off

post a pic,not all the digital gauges had an overtemp icon,some the overtemp was in the speedo.
if the far right bar over the green square is lit the oil system isnt the alarm.from there it will be battery level,water in the fuel,if equipped with it,or overtemp.

Re: OX66 oil/temp alarm going off

Took her out today, she gave me some mixed signals...running both motors at around 3600 rpm was the first time the alarm lit off and both motors went into rpm reduction, I brought the boat down off of plane, and put the port motor in neutral first. Alarm stayed on. Alarm ceased when I put strbrd motor in neutral. Turned off the strbrd motor and tilted it up, cranked the port over and attempted to take off. No dice. Still wouldn't go above 2k (after turning both keys off). Lifted the port and dropped the strbrd and took off just fine. I would assume the reason for the alarm not ceasing until I put the strbrd motor in neutral is because of how they are wired, sort of like only the port tach shows tilt. I have seen the strbrd motor temp gauge bars increase before when it ran hot b/c of a thermostat sticking, I've never seen the bars at all on the temp gauge for the port motor. I'm beginning to wonder if I'm overheating after all, and the bars on my port tach don't work for some reason. They come on at key on. so I know they are there. First picture is kind of hard to see, it was taken out on the water, while the alarm was going off. Nothing on any of the gauges was flashing.

Second pic, in the driveway hooked to the hose, display exactly the same (other than the fact that the strbrd motor is off)

Re: OX66 oil/temp alarm going off

Quick update, I pulled both of the thermostats out of my port motor, and they were both just barely open, like maybe a millimeter or two. I put them in a pot of hot water, and they didn't open up, even when the water was boiling...that is probably the culprit. Now I have to figure out why the temp reading on my tach didn't go up, and hope that no real damage was done...

Re: OX66 oil/temp alarm going off

there are no sensors involved with any alarms on an OX66 engine.
no oil flow sensors or switches,period.
a crank and stop signal simultaneously will trigger an alarm.
water detect,if equipped, will trigger an alarm.
low battery voltage,detected by the ECU not the speedo,wil trigger an alarm.
low engine oil tank level will trigger an alarm.
to test the tach visuals,
locate the pink wire at either head temp switch.
turn the key on.
unplug the pink wire and short the engine harness side to ground.
audible should sound at the temp icon flash.
no flash check the integrity of the gray wire from the engine 4 pin trim harness to the tach.

to test oil system alarm.
turn the key on,unplug the 4 pin connector at the remote oil tank,center bar should illuminate and /or flash in a few seconds.
with connector still unplugged drain the engine oil tank via the water trap tube until the audible sounds,tach should indicate low oil by the far left bar.
turn key off.
recconect all removed items.
make sure remote tank is at least 1/2 full.
turn key on
tach should show 3 bars flashing,transfer pump should turn on,engine oil tank should refill in 180 seconds,not quite full if its a 3.1L.

Re: OX66 oil/temp alarm going off

ledslinger29 said:

Quick update, I pulled both of the thermostats out of my port motor, and they were both just barely open, like maybe a millimeter or two. I put them in a pot of hot water, and they didn't open up, even when the water was boiling...that is probably the culprit. Now I have to figure out why the temp reading on my tach didn't go up, and hope that no real damage was done...

Click to expand...

When was the last time you serviced the pumps,stats,and PRV on both motors. I think I would be doing the other one also

Re: OX66 oil/temp alarm going off

99yam40 said:

When was the last time you serviced the pumps,stats,and PRV on both motors. I think I would be doing the other one also

Click to expand...

Did both water pumps in march, fuel water seperators/engine fuel filters last month, went and bought four new thermostats this morning. Haven't done PRV yet. What do I need to replace along with the valve? I assume the gasket, what about the spring and grommet?

Re: OX66 oil/temp alarm going off

I would pull and inspect to see if they just need cleaning or need to be replaced.

Re: OX66 oil/temp alarm going off

So I finally got to put the old girl back in the water after replacing the thermostats 2 weeks ago. No more alarm, no more reduced throttle state. Now I have to figure why the temp gauge on my port tach never showed any bars....I took the boat out to see if my alarm problem was gone (it is), now port motor is shutting off intermittently, high rpm, mid-range, idle, doesn't matter. Sometimes runs long, sometimes a few seconds. It starts right back up everytime. I pulled off the lift pumps, and one of them had a small tear in the diaphragm, so I replaced them both. Back to the water I guess...

Re: OX66 oil/temp alarm going off

That was it. Lift pump diaphragm was bad. Ran her tonight at 50 knots for 20 minutes, came down, idled for 20 minutes, brought her back up to 50 with no issues. Just to recap, I started with an intermittent issue, that only occured when I hit a wave offshore, which turned into an alarm (seperate issue), then turned into motor keeps shutting off. In this process, I have replaced plugs, VST filter, fuel filter, and finally lift pumps, as the two diaphragms 25 bucks apiece, and the whole pump was only 60. The thermostats were an incidental problem that happened to occur at the same time, that threw me way off track for awhile, they are now new as well. Now I still need to figure out why my tempurature bars aren't working on my port tach, but at least I'm back in the saddle.