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Survey of Yamaha Water Pressure Sensor Failure

Posted: Sun Aug 11, 2019 10:37 am
by El Rollo
SURVEY QUESTION: To owners of Yamaha outboard engines operated in saltwater that have a Command-Link gauge and a remote water pressure sensor: has the sensor ever failed?

BACKSTORY: I re-powered my 1988 15 Whaler a few years ago with a Yamaha F70 and chose the Command-Link gauge. I also purchased the remote water pressure sensor so that I could get the water pressure reading all on one gauge. At around 200-hours the sensor unit failed, and I replaced it at the cost of around $200 for the part, during a 100-hour service. The second sensor has failed in under 100-hours from the time of installation.

As you can imagine, I am frustrated as this is the second sensor in approximately 200 hours. The boat is primarily used in saltwater, and I am religious about flushing my engine within 10 minutes of putting it back on the trailer. I will occasionally use a 'Salt-a-way' product with the flushing attachment as well.

I did some on-line research and found a thread on a site where a boat owner had complained about a similar scenario. (He had a larger Yamaha) In the same thread, there was mention of Yamaha changing this part due to common failure problems. When I had the motor serviced, the technician tried to clean the sensor to see if he could get it to work, to no avail. I asked the technician if there was excessive corrosion or salt build up inside the motor and he said, "No, everything looked real clean".

I'd rather not have to add a separate water pressure gauge if I don't have to, The whole idea of the command link gauge was to have everything in one place. I'm hoping that I don't have to include an additional $200 part every time I need a 100 hour service.

Thanks in advance.

Re: Survey of Yamaha Water Pressure Sensor Failure

Posted: Mon Aug 12, 2019 12:16 pm
by biggiefl
Not sure if I have one on my 2004 F115 as I just bought it and have not messed with the command link yet. I do not have any warning lights or such stating to check my engine.

Re: Survey of Yamaha Water Pressure Sensor Failure

Posted: Tue Aug 13, 2019 10:09 am
by Jefecinco
Is it possible that frequent flushing with a hose at city water pressure could could be damaging the cooling water pressure sensor? Have you checked the pressure reading while flushing the engine? If the reading is much higher than the reading while the engine is operating it may be useful to moderate the pressure at the faucet.

Re: Survey of Yamaha Water Pressure Sensor Failure

Posted: Tue Aug 13, 2019 10:28 am
by biggiefl
Good point!

Check your owner's manual for any type of warning.

Re: Survey of Yamaha Water Pressure Sensor Failure

Posted: Wed Aug 14, 2019 11:38 am
by El Rollo
The locations I flush the motor at don't seem to have excessive water pressure.
If I do ever experience excessive pressure, I always 'gate-down' the flow so as not waste water.
With the 'ear-muff' style flushing attachment, any water not entering the motor intakes, seem to spill-out around the edge of the muffs.
I keep the pressure regulated so there is very little water spilling out and have never had a problem.
I'm thinking there is just a simple design flaw in how that pressure sensor is made, making it prone to clogging and ultimate failure.

Re: Survey of Yamaha Water Pressure Sensor Failure

Posted: Wed Aug 14, 2019 2:24 pm
by El Rollo
The reading from the sensor to the Command Link gauge is displayed in 'Digital bars' similar to those indicating reception on a cell phone. It does not display at 'PSI Value" . I do not know what each 'bar' represents in terms of 'PSI per bar, I simply use it as a point of reference. We have lots of kelp here on the west coast, as well as trash and floating plastic bags. I liked it for peace of mind.

Re: Survey of Yamaha Water Pressure Sensor Failure

Posted: Wed Aug 14, 2019 9:32 pm
by OldKenT
El Rollo,
The operation manual for my command link (square) multifunction meter shows a 5 bar water pressure scale at page 9 of the manual with the second bar from the left end identified as 10 psi and the fourth bar identified as 20 psi. That layout suggests a psi to 5 bar scale relationship of 5, 10, 15, 20, and 25 psi, with the extreme left of the scale being zero psi. The manual also has the statement "when the cooling water pressure decreases to 10 psi or less, turn the engine off and check the cooling water inlet for clogs." I don't know whether an alarm sounds at that psi.
I have an F70 with a water pressure sensor installed in Spring 2018. It has not had a problem to date, but my hours are far fewer than yours.
Also, Simrad MFDs will show Yamaha engine data with a NMEA 2000 network, so that could present a way of verifying the functioning of the sensor.
Ken

Re: Survey of Yamaha Water Pressure Sensor Failure

Posted: Thu Aug 15, 2019 8:56 am
by jimh
So far there are no responses to the survey question.

Re: Survey of Yamaha Water Pressure Sensor Failure

Posted: Fri Aug 16, 2019 7:48 am
by OldKenT
I should have been more clear. My F70 was installed in Spring 2018 with a water pressure sensor, both in new condition, and the water pressure sensor has not failed.

Re: Survey of Yamaha Water Pressure Sensor Failure

Posted: Sat Aug 17, 2019 2:47 pm
by conch
Among myself and my two next door neighbors we have 9 F300 Yamaha's all 2015 4.2 L models put in service in 2016. We all have the optional water pressure sensors and battery isolator leads installed since new. All motors run in very warm salt water. I rinse my motors religiously after each use, my neighbors rarely rinse. Over 10,000 hours between us and no water pressure sensor problems yet. Actually there have been no problems, only routine maintence.

I notice the 4.2L sensor attaches directly into the block without any hose or tubing. Maybe there is more water pressure to keep them from fouling compared to the F70 type of installation.

There is mention on Yamaha websites of a service bulletin regarding faulty sensors but I believe it was from 2009. Your dealer have old stock?
Maybe a call to Customer Service by you for some good will, if your dealer won't call for you.

Not much pressure anyway, I have Command Link Plus and when water is set to PSI the scale reads 5-25. I usually see 15 and higher above 3000 rpm.

Un-cited wrote:What is the minimum water pressure required for my Yamaha outboard(s)?

All Yamaha outboards have a minimum water pressure of eleven (11) psi at Wide Open Throttle (WOT). There are no announced water pressure specs for low or mid-range operation at this time. This is due to our high volume low pressure cooling system design. In fact, you may see zero pressure at idle, as most water pressure sensors start working at 3-psi
.

Re: Survey of Yamaha Water Pressure Sensor Failure

Posted: Tue Aug 27, 2019 11:08 am
by jimh
If I am correctly tabulating the survey results, so far there are no reports of a failure of a Yamaha engine water pressure sensor (other than the one cited in the initial report of a failure that solicited the survey).

Re: Survey of Yamaha Water Pressure Sensor Failure

Posted: Tue Aug 27, 2019 12:22 pm
by El Rollo
I've scheduled an appointment with the local Yamaha dealer/service center where I purchased and had the sensor installed.
The dealer is very close to my house, and since the part is $200 and has less than 100 hrs on it, I feel it's worth it.
I will report my findings here.

Re: Survey of Yamaha Water Pressure Sensor Failure

Posted: Tue Aug 27, 2019 4:05 pm
by jimh
In the for-what-it's-worth category: with the early E-TEC engines Evinrude had some problems with a water pressure sensor. The sensor was apparently failing in saltwater. I cannot say for certain, but I think the sensor was originally mounted directly to a boss in the block in the cooling water passages. The sensor orientation was horizontal, which may have permitted saltwater to remain in the sensor when the engine was not in use.

The remedy (or part of the remedy) was to relocate the sensor to be connected by a length of hose, with the sensor oriented above the boss port. In this way, any saltwater that got into the sensor would drain out. The sensor orientation was changed to be vertical to further promote draining out. Also, with air trapped in the line, water would never even get to the sensor. The water would push on the air, and the air would push on the sensor. Water, saltwater or freshwater, never got to the sensor itself.

I have one of these sensors. It has worked flawlessly for me. It has been almost exclusively in freshwater. You can see the installation of it in an article I wrote at

http://continuouswave.com/whaler/refere ... g.html#psi

I have no knowledge of how Yamaha implements their water pressure sensor. The approach used by Evinrude might be possible method to employ with the Yamaha sensor, that is, moving the sensor to a higher point, orienting it so water drains out of it, and connecting to the cooling passages via a small hose.

Also, the notion that the sensor costs $200 is just crazy. The sensor Evinrude used is also expensive as an OEM replacement part, but several E-TEC owners found that a $20 sensor sold on AMAZON and probably from an automotive CANBus application worked as an exact replacement. The sensor operated from 5-Volts and had a linear voltage output that corresponded to pressure input. See

https://www.etecownersgroup.com/post/sh ... rum=115574

Note that in the Evinrude approach, the sensor actually just puts out a voltage. The engine management module converts the voltage output from the sensor into a water pressure value and sends the data to the NMEA-2000 network via the engine's network port. If the Yamaha sensor is similar, one of the Amazon sensors might be a replacement.