Why You Should Inspect Your Foam Air Filter Element

Dec 19, 2006
5,809
Hunter 36 Punta Gorda
I tried using a K&N filter but it resulted in so much more noise as I was in
the cockpit that I went back to the stock filter and no problem with the foam filter.
Nick
 
Feb 6, 1998
11,665
Canadian Sailcraft 36T Casco Bay, ME
Guys,

Two words; BELT DUST...... The components of v-belt dust can mean damaging wear for a marine engine. Some of these v-belts are made with highly abrasive arimid/Kevlar tension cords in them that when turned into airborne dust can actually be abrasive to engine internals (confirmed for me by Gates Engineering department). Unlike a car, our battery banks demand huge loads from the alternators and this results in belt dust. In essence the engine is creating its on damaging dust in a very small space....

Brand new:


Same filter after two seasons use..
 
May 12, 2004
1,502
Hunter Cherubini 30 New Port Richey
Thanks for the heads up. Replaced the original YSB12 in '07 with a 3YM20. Need to get down to the boat and check the filter. It's been awhile. BTW, the YSB12 never had a filter, only an air intake. Never a problem. In fact, one time motoring out the river, I went below to check things out and went to wipe a bit of oil. That intake sucked the paper towel right out of my hand. :yikes: Engine stopped immediately. Took the intake off and pulled out what I could from the valves. Let her sit awhile while the diesel soaked the paper. Cranked her and after a couple of coughs she started right up and spit the remaining bits of paper right out the back. Tough little diesels. Although I don't recommend paper towels as an additive.
 

Gunni

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Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
I hear you Maine, my concern is that we do not have air flow ratings for our engines (cu.ft/min) or flow ratings from the filter manufacturers. When I contacted K&N they told me they will not provide any fit recommendations for random marine applications - go to the engine manufacturer. Yanmar is mute. A restricted intake is as much a concern for me as whatever random dust may be floating about the engine bay.
 
May 12, 2004
1,502
Hunter Cherubini 30 New Port Richey
Went to the boat this afternoon. Took the canister off and the foam filter was a good 70% gone. Going to get a replacement soon. What is the K and N air filter element I keep reading about and seeing in pics and where does one find it? Is it adaptable to my 3YM20? Thanks.
 
Feb 6, 1998
11,665
Canadian Sailcraft 36T Casco Bay, ME
I hear you Maine, my concern is that we do not have air flow ratings for our engines (cu.ft/min) or flow ratings from the filter manufacturers. When I contacted K&N they told me they will not provide any fit recommendations for random marine applications - go to the engine manufacturer. Yanmar is mute. A restricted intake is as much a concern for me as whatever random dust may be floating about the engine bay.
You simply measure the ID if the intake, the engine can't swallow more than the ID will allow for, and call K&N. K&N has given me this information numerous times when I asked about cross section area vs. filter media % and potential for restrictions... The filters I install have 1.7X to 2.5X the air flow ability to the ID of the intake. These filters are used on every high HP application known to man.
 
Jul 7, 2004
8,402
Hunter 30T Cheney, KS
I use the K&N drop-in filters on my cars today. I had a K&N cone filter on my TurboCoupe. I'd like to figure out if one will work on my 2GM20F. They call it a 'silencer' though. will the engine run noisier than it already does? Not that it matters really.
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
You simply measure the ID if the intake, the engine can't swallow more than the ID will allow for, and call K&N. K&N has given me this information numerous times when I asked about cross section area vs. filter media % and potential for restrictions... The filters I install have 1.7X to 2.5X the air flow ability to the ID of the intake. These filters are used on every high HP application known to man.
they are also known as the million mile filter i tried one on a trip to Florida about 15 years ago and could see a differance in milage and performance.....in a pickup truck....they are what they say they are
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
[QUOTE.... They call it a 'silencer' though. will the engine run noisier than it already does? Not that it matters really.
Justin, the filter keeps out dirt and INSECTS. Those little buggers go down kicking and screaming unless you keep them out- thus the silencer name.
 

Gunni

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Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
I'm working on the install of a hybrid K&N filter with a closed crankcase breather system. It will provide air filtration and engine vapor recovery to control engine fumes. Pics to follow.
 
Oct 26, 2010
1,883
Hunter 40.5 Beaufort, SC
I'm working on the install of a hybrid K&N filter with a closed crankcase breather system. It will provide air filtration and engine vapor recovery to control engine fumes. Pics to follow.
Looking forward to seeing your pics - please post them as soon as you get it installed.
 
Apr 20, 2016
1
Pearson 39-2 Annapolis, MD
Just a word regarding air filters and elements. My Yanmar has the air filter mounted on the side and features a tapered inlet horn. I once made the mistake of replacing the assembly and aiming the end at the two o'clock position instead of the 4 or 5 o'clock. My ending resides below a double sink i the galley. Great access. But last year the drain leaked. The water from the sink filled the air input and the cylinders. Only after cranking to clear the water was I able to get it started. I also had to release the cylinder pressure as the pressure was so strong the ending would not crank. Happy cruising folks.
 
Dec 19, 2006
5,809
Hunter 36 Punta Gorda
I have a 2007 H-36 with 3YM30 and tried the K&N filter but the noise up in the cockpit
was so bad that I decided if my wife was down below while motoring she would kill me.
I thought the noise was too much just from the cockpit and now have the K&N home in my garage and my foam air cleaner has never been a problem.
Nick
 

Gunni

.
Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
My intake silencer incorporates a crankcase breather that allows oil to show up in the silencer (hence the reason for John's intake horn angled downward to all condense oil to drip out into the bilge). I wanted to keep that feature and attempted to squeeze a nicely designed intake system with a K&N filter into my engine bay. The system, from Walker Engineering was designed for universal use in gensets and small diesels like my 2ltr Yanmar. Includes a restriction indicator to show you when to clean the filter. But alas I could not make it fit in the bay. But if you want the whole system (silencer, breather, oil drain to pan and all the parts to mount it, take a look at Walker Engineering's stuff. West Marine has them on sale for $200
http://www.walkerairsep.com/product_detail.asp?id=564
 
Jul 7, 2004
8,402
Hunter 30T Cheney, KS
Just as a word of caution, I found this hole eroded through the foam air filter element when winterizing our Yanmar 3YM30 engine last Fall. The hole was at the point where the air flows into the silencer. My assumption is the element had not been changed since the boat was new in 2008 :cuss:and a diesel engine runs just fine on a little bit of foam...:yikes:
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The February issue of Practical Sailor pretty much summed this thread up in an article named "In Search of Better Filters". They even used this picture. Noisier or not, I think I'm going to find a K&N that fits my 2GM20.
 
Jul 4, 2015
436
Hunter 34 Menominee, MI; Sturgeon Bay WI
When I bought my '86 boat 5 years ago, the 3GM30 filter foam was gone with just the metal mesh remaining. Had obviously been ingested by the engine. This in a boat operating in a cold pristine environment with the boat stored every winter.
When we tore apart the engine the following year (for a leaking main seal) and completely rebuilt it, there was no evidence of any harm done by this.
The real harm was what I thought of the previous owner and their lack of thoughtfulness/care for their machine. As a very mechanically sensitive person a few choice words came/ still come to mind. I guess different priorities.
 

Blitz

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Jul 10, 2007
672
Seidelmann 34 Atlantic Highlands, NJ
I inspect mine twice a year; I've always made it a habit after winterizing to remove the air filter assembly and block the intake hole for the winter to keep the salty air out. You can squirt some fogging or WD40 to protect it as well. With this method you can't help but inspect the element twice a year: probably when you took it off and again when you reassembled it in the spring.
 
Oct 6, 2007
1,023
Hunter H30 1982 Chicago IL
I replaced mine five years ago when I discovered crumbly foam. It’s on my spring check list, but this post prompted me to look at it Sunday when I was at the boat for my monthly winter storage check. The foam was a little dirty right at the intake hole, so I just rotated the filter position, which I have done a few times in the past. This tells me the design doesn’t really allow air flow through the whole filter area.
 
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Jul 7, 2004
8,402
Hunter 30T Cheney, KS
The cone would open up the restriction of the silencer, but I read that they are noisy. Hence the silencer.