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Author Topic:   1991 Yamaha 200 oil problem
6992WHALER posted 10-26-2011 11:33 AM ET (US)   Profile for 6992WHALER   Send Email to 6992WHALER  
I have twin 1991 twin 200 Yamaha 2 stroke engines .
My port engine will sound a low oil alarm after about 30 minutes of planing.
The oil tank on the engine will be at the low level line but there is plenty of oil in the main tank.
If I shut down the engine and turn the key on the oil pump in the main tank kicks on and fills the engine tank, and I am good to go for another 30 minutes.
If I cruise at displacement the engine oil tank appears to fill just fine.
I took the float out of the sender on the top of the engine and cleaned it and the screen but doing this had no effect.
I have noticed on parts diagrams that there is an inline "strainer" between the main tank and the engine. I wonder if that could be partially obstructed?

Has anyone else experienced this problem?

conch posted 10-26-2011 01:30 PM ET (US)     Profile for conch  Send Email to conch     
The small quarter size in-line oil filter may be clogged.

It is located outside of the main tank next to the pump.

This is very easy to change,and a good time to drain and clean the tank.It sounds like everything else is working.


contender posted 10-26-2011 08:05 PM ET (US)     Profile for contender  Send Email to contender     
Conch is correct: The yamaha's oil tanks has a filter that needs to be cleaned, remove the tanks, drain the oil, clean them out and the filter, I would blow out the oil line as well and do the small tanks on the engine as well.
DAVIDinMS posted 11-02-2011 12:05 PM ET (US)     Profile for DAVIDinMS  Send Email to DAVIDinMS     
I had a 1991, 200. It had a tilt sensor to tell the oil tank to not send oil if the motor was tilted up. Can't remember all the specifics, but i had a choice to bypass it or replace the trim sensor.
6992WHALER posted 11-02-2011 11:13 PM ET (US)     Profile for 6992WHALER  Send Email to 6992WHALER     
I hope to get a chance to look at it on Friday. I was all pumped up to change out the filter and have it fixed.

Now I will need to do some research on trim sensors.
I hope the filter is obviously blocked that would make life simple.

6992WHALER posted 11-14-2011 04:30 PM ET (US)     Profile for 6992WHALER  Send Email to 6992WHALER     
I pulled the filter/strainer off today. Took longer to drain the oil out of the tank then it did to pull the filter.

They only cost about $6.00 so I think I will order 4. I will replace them on both engines now and then carry two extras so if this happens again I can fix it on the spot.

Of course I will not know if this actually fixed it until next spring.

Thanks for the input.

6992WHALER posted 07-13-2012 01:21 PM ET (US)     Profile for 6992WHALER  Send Email to 6992WHALER     
Changing the little oil filters did not fix the problem.

The engine still gives me a low oil alarm after about 30 minutes of planing.

Any other ideas?


jimh posted 07-13-2012 11:30 PM ET (US)     Profile for jimh  Send Email to jimh     
John--As I recall, the oil system on your c.1991 Yamaha 200-HP outboard motors uses two oil reservoirs. The main oil reservoir is a remote tank. Under the engine cowling is a second oil reservoir. I believe that the oil is lifted from the remote tank to the under-cowling tank by an electrically operated pump. The pump is controlled by a float switch in the under-cowling tank. The remote tank keeps the oil level in the under cowling tank at a mostly-constant level and near full.

The alarm sender is probably located in the under-cowling tank--I am working from memory here so this may not be precisely accurate. When the oil in the under-cowling tank drops below a certain threshold level, an alarm is sounded. If the system is working properly, this low level in the under-cowling tank is never reached because the electrical lift pump keeps the under cowling tank full.

Based on your narrative of the symptoms and circumstances, the most reasonable inference for the source of the problem is the electrically operated lift pump for the remote oil tank. This pump must not be able to keep up with demand for oil when you are running the engine at higher speeds. The output of the electric lift pump must be insufficient to keep the under-cowling tank full when the engine is consuming oil at a high rate. After 30-minutes the difference in supply of oil and demand for oil causes the level in the under-cowling tank to drop below the alarm threshold.

Give the electric lift pump a close look. Perhaps it has a problem with its pick-up tube, or perhaps the hose has a kink. There could also be a problem with the float switch that operates the lift pump. It may not be working correctly. If the contact of the float switch has high resistance, the pump may not be able to run at full power.

I think there is a manual over-ride switch under the cowling that forces the lift pump to run. Operate this switch and see if the pump produces a strong flow of oil into the under-cowling tank.

rtk posted 07-14-2012 08:25 AM ET (US)     Profile for rtk  Send Email to rtk     
Jim's advice is good. My buddy had a similar problem with his 1986 Yamaha 115. The oil pump on the remote oil tank was failing and only worked intermittently.

I pulled the pump off the tank and it was extremely rusted. I was suprised that it worked as long as it did. Replaced the pump and all was well.

The pump is just pressed into the plastic tank- just pry it out if I remember correctly- easy fix.


6992WHALER posted 07-18-2012 10:42 AM ET (US)     Profile for 6992WHALER  Send Email to 6992WHALER     
I ordered a new pump today. Hopefully that will solve the problem. I am replacing a 21 year old pump so even if it does not fix it, I do not feel bad about replacing it.
Either way I will carry the old pump as a back up.
6992WHALER posted 07-21-2012 11:07 PM ET (US)     Profile for 6992WHALER  Send Email to 6992WHALER     
The pump arrived today.
It took me about 10 minutes to replace the old pump.
All it took was two wire ties on the two hoses and plugging in the two power wires.

I did not get a chance to run 30 minutes on plane so I don't know if it fixed it.

6992WHALER posted 08-13-2012 06:07 PM ET (US)     Profile for 6992WHALER  Send Email to 6992WHALER     
Well, the pump did not fix the problem.
Looks like my next job is to replace the Oil Level Gauge in the under the cowling oil tank.

Could this be caused by a dirty oil strainer that the Oil level gauge sits in (part 25 in the diagram)? OIL%20TANK/parts.html

6992WHALER posted 09-05-2013 06:11 PM ET (US)     Profile for 6992WHALER  Send Email to 6992WHALER     
I have finally found the source of the oiling failure.

The trim sensor on the port engine was stuck reading full trim. The oiling system is designed to not move oil from the main tank to the engine tank when the engine it trimmed above 30 degrees.

The trim gauge read full trim when I bought the boat and I never cared. I don't use a gauge to trim my engines. I still have trouble understanding why the engine would transfer oil with the key on but engine off. One would think that the system would always read the engine tilt and would never allow oil to be transferred.

So after replacing the filters, the oil pump and the oil level sensor all I needed to do was spray some penetrating oil on the trim sender and work it around a little and the problem is fixed.

I do not feel too bad about replacing 20 year old parts, and now I have a bunch of spares.

Now the big question, how did I (and Jim H as well) miss this suggestion from DAVIDinMS in November 2011. He nailed it right out of the box.
DAVIDinMS if I ever ignore your advice again please yell louder. Thanks

"I had a 1991, 200. It had a tilt sensor to tell the oil tank to not send oil if the motor was tilted up. Can't remember all the specifics, but i had a choice to bypass it or replace the trim sensor."

jimh posted 09-05-2013 08:58 PM ET (US)     Profile for jimh  Send Email to jimh     
Thanks for the follow-up to give the solution.

I recall we had a long telephone conversation on this topic and I suggested buying a $2 resistor at Radio Shack to substitute for the tilt sensor.

By the way, when you have really accurate indication of engine trim, that information is very handy. I use my engine trim gauge, which reads from 0-100 over the range of operating trim, as a way to accurate set the engine trim to a known position that will give me best performance and economy. It is much easier than fiddling around with the position. It is also safer than looking astern all the time to see where the engine tilt position is. When you have tilt position indication with really fine resolution, it is quite useful.

I don't quite understand how the pump would operate with the key in RUN but the engine not running. How did the system sense the engine was not running? What input sensor did it use to deduce that the key was in RUN but the engine was not operating?

6992WHALER posted 09-05-2013 09:55 PM ET (US)     Profile for 6992WHALER  Send Email to 6992WHALER     
I don't know but if I turned off the engine and then turned the key back on the pump would fill the tank?

I think it would have been easier to figure this out if it had just stopped pumping all together.

In the beginning I was on the wrong track of thinking that the system could not keep up when the engine was running at higher RPMs. Dirty filter or an old weak pump. When those proved to not be the cause.

I figured it had to be a faulty oil level sensor, it was not.

I just stumbled over a sentence in a service manual about a 90 hp Yamaha that mentioned the oil shut off, if the engine was tilted up. Once I added engine trim sensor to my web search I found a lot of info on this problem.

Jeff posted 07-23-2015 05:49 PM ET (US)     Profile for Jeff  Send Email to Jeff     
DAVIDinMS and John,

Interesting find with the trim switch. We are actually having the same problem / alarm and low tank situation on one of our 1993 Yamaha 150's and the trim indicator is always reading full trim. This has to be our problem as well.

6992WHALER posted 07-23-2015 09:18 PM ET (US)     Profile for 6992WHALER  Send Email to 6992WHALER     
I would bet on it. Easy to check just wire the trim sensor in the down position and watch your problem go away.

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