# Auto oil filter on a marine engine?



## DW2018 (Aug 21, 2018)

Ordered a 100 hour service kit a few days ago, getting ready to do the service on my recently acquired 2005 Yammy 115. When I took the cowling off yesterday, I found that the oil filter on the motor was a NAPA Gold automobile filter. I'm all for saving a few dollars here and there but it doesn't seem to me that using an auto filter on a marine engine is the best place to try to save a few bucks. Just wondering if this is common practice or not. I'm not convinced an auto filter is designed to perform equivalent to a filter designed specifically for a marine engine but I'm not a marine motor engineer so maybe it's not a big deal.




  








Filter




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DW2018


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Oct 10, 2018


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## Guest (Oct 10, 2018)

Provided the filter is spec’d for the engine it will be fine. I don’t reccomend anything but factory parts to my customers because I know they are right! Only so many ways to build a filter though, filter micron, bypass relief pressure is about it other than thread size/pitch.
Fact is, only so many factories making oil filters and your napa filter is probably made in the same plant as the Yamaha.


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## DW2018 (Aug 21, 2018)

Thanks Boatbrains. I have no idea whether the NAPA Gold filter is spec'ed for this motor or not and from what I've read the NAPA Gold filter is a decent (auto) filter, so I'm not losing sleep over it. At least it wasn't a Fram...

The Yamaha filter is reportedly built a bit different than typical pleated filters, at least that's what someone in THT posted after cutting one open (see photo below) and according to at least one Yamaha youtube video. More of a molded polyester.




  








Yamaha




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DW2018


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Oct 11, 2018








Fortunately, so far the motor runs well so I don't think there's a problem with it. I think the 100 hour service kit I ordered from Simyamaha comes with a Yamaha filter and I'll probably stick with OEM, or at least marine-specific functional equivalents, going forward.


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## Guest (Oct 11, 2018)

That sounds like a solid plan to me! They are a little different as noted, as long as it was spec’d you are ok. And from the sound of it, motor is doing fine so just do as you said and you’ll be fine.


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## yobata (Jul 14, 2015)

On my truck, I use a Wix filter... The 2 stoke Yamaha 25hp doesn't need a filter


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## devrep (Feb 22, 2009)

so you never noticed this before?


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## DuckNut (Apr 3, 2009)

There are pressure springs inside and do you know if the pressure to open the spring is greater than the pressure your engine can produce?


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## DW2018 (Aug 21, 2018)

devrep said:


> so you never noticed this before?


Hi devrep. Bought the boat less than two weeks ago, noticed the unusual oil filter a few days later. Probably should have noticed it before buying but the wet test was solid,the engine runs great. I don't think I would have been deterred from purchasing the boat had I noticed the filter. Engine had 92 hours since the 300 hour service when I got it, has 95 hours on it now, I decided to do the 100 hour service a few hours early. Thanks for asking.


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## DW2018 (Aug 21, 2018)

DuckNut said:


> There are pressure springs inside and do you know if the pressure to open the spring is greater than the pressure your engine can produce?


Great question. The low oil pressure warning hasn't come on while I've operated it. I should get a manual gauge and check it. Either way, the filter's getting replaced with a marine filter before I take it out again. Is there a standard pressure required to open an auto oil filter?


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## devrep (Feb 22, 2009)

the only valve I'm aware of is a bypass valve if the pressure gets too high. Except Toyota filters also have a backflow valve to keep the filter full after the engine shuts off.


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## Guest (Oct 12, 2018)

devrep said:


> the only valve I'm aware of is a bypass valve if the pressure gets too high. Except Toyota filters also have a backflow valve to keep the filter full after the engine shuts off.


This is correct!


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## firecat1981 (Nov 27, 2007)

I've been using the Napa filters for a while with no ill effect. I needed a filter for a last minute oil change prior to a trip and had no luck getting one local. So I consulted the brain trust here and on THT and was surprised to find many guys had switched away from the manufacturer specific. Do a search, some mechanics even went as far as to take them apart for comparison.


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## devrep (Feb 22, 2009)

no oil filter needed.


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## jonrconner (May 20, 2015)

I rather think that oil filters are oil filters, does anyone really think that a filter spec for Yamaha outboard is any different from a filter speced for a Porsche?
Seriously!
JC


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## devrep (Feb 22, 2009)

I've seen some tests where they cut open a bunch of filters and some were pretty cheesy. having said that, maybe cheesy is good enough to do the job.


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## Guest (Oct 13, 2018)

jonrconner said:


> I rather think that oil filters are oil filters, does anyone really think that a filter spec for Yamaha outboard is any different from a filter speced for a Porsche?
> Seriously!
> JC


Yes, the specs are different between motors of same brand even! Careful JC sometimes knowing too much can be expensive! The bypass pressures are the biggest issue. I had a filter on a vehicle once that never saw a drop of dirty engine oil for 3k miles due to being the wrong filter and bypass pressure not being equal to what the engineer required! Oil pressure was good it just wasn’t being filtered for 3k miles! Manufacturer A may build to a tighter tolerence than manufacturer B and require greater filtration in the “micron” department also. 
But, like I said originally... if the Napa filter meets OE specs then all is good!


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