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Runamuk · 09-02-2016, 05:58

Last week I was doing my pre-Spring maintenance by replacing fuel filters and changing the oil/filter. I removed the cover for my air filter and all thats in there is a perforated metal cone, there is no filter? this can't be right.

I have owned this boat for just over a year and I'm kicking myself now for not checking this earlier. Does anyone know what PN filter or an equivalent filter that I can use, I've heard that there is supposed to be a piece of foam wrapped around the metal cone but I would prefer to use a real filter element if possible.

Thank you in advance

transmitterdan · 09-02-2016, 06:05

I think you will find this is normal. Don't add a filter without talking to manufacturer rep.

Rhapsody-NS27 · 09-02-2016, 06:23

There should be a foam filter and not just the metal piece.

The part number is 128270-12540 found on page 20 of this parts catalog for your engine.
http://www.lsm-diesel.dk/2012/yanmar...le_3gm30-f.pdf

rwidman · 09-02-2016, 06:26

I would use the manufacture's filter as above. A boat is a little different than a car or truck. You won't be boating down any dirt roads.

four winds · 09-02-2016, 06:35

I'm in the same boat.

The manual shows what looks like a foam filter wrapped on the screen. I wonder if they deteriorate and get slowly eaten be the engine. Hope not.

Would like to fit a washable filter such as K&N. Maybe one that could be modded to fit inside the factory housing.

Ribbit · 09-02-2016, 06:36

The Yanmar foam filters work pretty well if you follow the cleaning/maintenance instructions (my Yanmar powered generator did over 30,000 hours while I had it, on the same filter, and it's still running well with my neighbour).

I changed the oil and washed and re-oiled the foam filter every 3 months. You can get air filter spray rather than using ordinary oil, but I didn't notice any benefit.

**a64pilot** · 09-02-2016, 06:41

There is dust on a boat though, sometimes a lot of belt dust, I know my airfilter was full of belt dust until I went serpentine.
I'd want an airfilter myself.

On edit, I fit a K&N on mine as I am real familiar with them.
But sometimes the airfilter housing is actually a noise muffler too, so often if you replace that housing with a K&N, the engine gets loud.
Ever "flipped the lid" on a car airfilter when you were a kid?

**a64pilot** · 09-02-2016, 06:42

Quote:

Originally Posted by four winds

The manual shows what looks like a foam filter wrapped on the screen. I wonder if they deteriorate and get slowly eaten be the engine. Hope not.

Yes, they do, exactly like the foam filter on a lawnmower

Ribbit · 09-02-2016, 06:51

Quote:

Originally Posted by a64pilot

Yes, they do, exactly like the foam filter on a lawnmower

Interesting point.

The one in my generator obviously wasn't as good as new after a fair number of years. Is there a recommended replacement period for them?

Diesels do like fresh oil and good filters (oil, fuel, and air), and I do like looking after them (spoiling them rotten even - it's always paid off for me, mine have always run much better when I sold them than when I have bought them), so an air filter change would be nice to schedule into the maintenance.

wiekeith · 09-02-2016, 08:03

I have a Yanmar engine (4JH4) that has no air filter whatsoever. Really threw me at first, prior to doing my first service on the engine, when I spent hours online trying to identify the part number of the non-existent filter in order to buy one.

**a64pilot** · 09-02-2016, 08:10

Quote:

Originally Posted by Ribbit

Interesting point.

The one in my generator obviously wasn't as good as new after a fair number of years. Is there a recommended replacement period for them?

To use an aircraft term, I believe it's on condition, meaning replace them when they show wear, not on a calendar date? I've had them tear when cleaning, time for a new one, but they do need inspecting I believe on every oil change as that's when I think about it.
If I had to bet, I believe it's petroleum oil that deteriorates the foam. I have never tried, but I'd think a vegetable based oil may not deteriorate the foam.
I use K&N oil as it's a little sticky and I believe it traps dirt better due to it being a little sticky.

four winds · 09-02-2016, 08:36

Quote:

Originally Posted by wiekeith

I have a Yanmar engine (4JH4) that has no air filter whatsoever. Really threw me at first, prior to doing my first service on the engine, when I spent hours online trying to identify the part number of the non-existent filter in order to buy one.

Part 129470-12330. Not much of a filter though. Notice the fine mesh around the inner part.

The older models have the foam around the part with the grid of holes.

My guess is the new style solves the degrading foam issue. I may consider using this new style. Looks to be the same dimensions.

Dennis.G · 09-02-2016, 08:39

No air filter on a marine engine is not unusual. Never had an outboard motor with an air filter. My diesel has a foam air filter, but very minimal thickness and leaky - don't think it really does much. Worry about oil and fuel filters instead.

four winds · 09-02-2016, 08:50

Quote:

Originally Posted by Dennis.G

No air filter on a marine engine is not unusual. Never had an outboard motor with an air filter. My diesel has a foam air filter, but very minimal thickness and leaky - don't think it really does much. Worry about oil and fuel filters instead.

Probably because the air doesn't have to pass through a fuel metering device such as a carburator or throttle body.

Any particulate matter present is inconsequential compared to the carbon present from burning diesel inefficiently.