Been a while since we've had an oil thread

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
14,575
Yeah in fresh water
In salt because of the way cast iron corrodes, those rust flakes WILL clog it.
 

Lpgc

Chief Petty Officer
Joined
Jun 17, 2023
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473
Not sure how much I trust the dash oil pressure gauge on my boat anyway.

I replaced the sender during the engine rebuild with a cheap one from Amazon. The new one seemed to work the same as the old one, as in the dash gauge pointed to the same pressure as before the rebuild, it was with that sender fitted that I tried various oils including the VR1.

But that sender broke after only 2 years use, had me worried a few times because the gauge would suddenly show zero oil pressure! But I quickly found the reason to be that the connector had become loose on the sender unit, so I knew it was just a sender problem not an actual oil pressure problem.

I bought another cheap sender from Amazon but this time I seem to have bought the wrong spec, it makes the dash gauge read a lot higher than actual pressure. I'll replace it with another correct spec sender over winter, only a 10 minute job.

I've never trusted the dash gauge because when I bought the boat none of the gauges worked properly, it has the 4Winns car like instrument cluster setup and for some reason before I bought the boat all the dials seemed to have moved and gauges like the oil pressure gauge didn't point to zero with ignition on engine off, I fixed that by removing the dials and putting them back on at the zero position with ignition on engine off. I don't think I'd trust the dash gauge to be totally correct anyway, even if it didn't have the problem with the dials... I would like to fit an accurate none electric gauge on the engine itself to compare the dash gauge reading to.

Another couple of things I need to fix over winter are the warning alarms for low oil pressure and high coolant temp, neither has worked since my first year with the boat. This year I tried replacing the single 'buzzer' with 2 separate buzzers but still neither alarm worked.

When the oil pressure switch (separate from the gauge sender) senses low oil pressure is it supposed to go to zero Ohms? IIrc mine goes to 15Ohms so it might be the oil pressure switch that's broken...
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
14,575
Yep they had a lot of issues with those car style dashboards, I recall some years back there was a guy on the ifourwinns.com board who knew how to fix them, and someone else who actually had a new dash panel made and replaced the car style unit with actual gauges, which to me is the best solution if you are keeping the boat a long time. My old 1988 still has the original Medallion gauges that were OEM and they are old looking but all still work. I do have a new set of Faria gauges but was too lazy to swap out something that still works!
'88 FW instrument panel.jpg
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
14,575
PS
I'd get an OEM style sending unit from
www.marineengine.com
just look up your engine, it's pricey but they work
I do not like buying any automotive/boat parts from amazon. Took much junk out there.

I'd probably buy the Sierra one
part #61
believe it or not mine still has the original one, don't know who made it but it still works!

PS if marineengine doesn't ship to the UK, see if you can find it locally, I'd guess Sierra parts are sold where you are, they are one of the biggest marine aftermarket companies there is.
 
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Lpgc

Chief Petty Officer
Joined
Jun 17, 2023
Messages
473
PS
I'd get an OEM style sending unit from
www.marineengine.com
just look up your engine, it's pricey but they work
I do not like buying any automotive/boat parts from amazon. Took much junk out there.

I'd probably buy the Sierra one
part #61
believe it or not mine still has the original one, don't know who made it but it still works!

PS if marineengine doesn't ship to the UK, see if you can find it locally, I'd guess Sierra parts are sold where you are, they are one of the biggest marine aftermarket companies there is.

I can buy a new oil pressure sender from the same place I bought the gimble bearing https://repowermarine.com/buy-volvo...-lubrication-system/oil-pressure-senders.html . Bit pricey hence why I cheapskated and bought one from Amazon hehe.

Don't know about marineengine.com, I have bought Sierra parts before (pistons etc) but that was over a decade ago when I rebuilt an early 80's Mercury 70 outboard that was on the little 14ft speedboat I had at the time, the supplier I used was in the US but I don't remember which supplier it was.
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
17,387
one guy brought up an interesting point, in markets outside the USA, Yamaha doesn't mention FW-C in specs required for oil grades, only typical automotive grades.
That's because FW-C is not a globally recognized oil designation such as SAE or API

FW-C® is in fact a trade mark of a certification created by the "pay to play" organization, the National Marine Manufacturers Association (NMMA)
 

eggs712

Chief Petty Officer
Joined
May 8, 2012
Messages
440
When the oil pressure switch (separate from the gauge sender) senses low oil pressure is it supposed to go to zero Ohms? IIrc mine goes to 15Ohms so it might be the oil pressure switch that's broken...
You may have a dual station sender. For a US Customary gauge, (test with no ignition power to a good ground), a single station sender should read 240 Ohm; a dual station sender will read 120 Ohm and would give high readings.
 
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