Yanmar 4BY2 air filter

rpmerrill

Well-known member
Joined
Feb 5, 2016
Messages
608
Fluid Motion Model
C-28
Vessel Name
BAY RANGER
It seems the more I look for an air filter, 120650-12510, the more expensive they get.

The last one I bought wasn't THAT expensive! I can't remember where I got it. (Maybe Spring 2019 - or 2018?)

Does anyone have a good source or substitute, even if it is cobbled up from bits and pieces.
Help!

Thanks
 
If the filter is in good condition other than being dirty they can be cleaned using a K&N cleaning kit. Auto part stores carry the kits or look on Amazon. I clean and oil mine as needed.
 
Yup, I used the K&N cleaner and it cleaned up surprisingly good.
The filter is still a little less than perfect looking (possible sucked in at high rpm?) But I'm sure it will still work ok.

The most common price I found for a new one was $170. I think one was ~$150 and one was like ~$214!

Thinking about all this I took my air filter to the local auto parts store. Got permission from the manager to "browse" the K&N boxes. I found a really nice match. Model number: E-0940. Everywhere I looked it was $62.99. 6" dia base, 3" dia at the top and 7-1/2 tall. Just misses hitting the fuel filter by my measurements.

It is a conical filter with a flat faced flange at the wide end. The flange is pretty wide so it is trimmable down to a dimension that would fit into the original silicone rubber filter base. (After a surgical removal of the old filter guts.) A couple small sheet metal screws with washers could hold the assy together.

The K&N filter has about 105 sq inches versus the Yanmar at about 95 sq inches.
We'll see how boring my winter gets.
 
Good work, Rich. And for those who want to take the Frankenstein project a step farther, the WIX catalog shows their 46289 as a replacement for the K&N, priced between $10 and $20 online. Same filter is available at NAPA as their 6289. Original fitment is 94-04 Ford Mustang. Vroom vroom!
 
Cap'n Crunch
The Wix looks really different but it might just fit.
The Wix is cellulose where the K&N is Cotton (oiled). One might be more reusable than the other but at that price ... who cares.

Thanks
r
 
rpmerrill":35vtkxtc said:
Yup, I used the K&N cleaner and it cleaned up surprisingly good.
The filter is still a little less than perfect looking (possible sucked in at high rpm?) But I'm sure it will still work ok.

The most common price I found for a new one was $170. I think one was ~$150 and one was like ~$214!

Thinking about all this I took my air filter to the local auto parts store. Got permission from the manager to "browse" the K&N boxes. I found a really nice match. Model number: E-0940. Everywhere I looked it was $62.99. 6" dia base, 3" dia at the top and 7-1/2 tall. Just misses hitting the fuel filter by my measurements.

It is a conical filter with a flat faced flange at the wide end. The flange is pretty wide so it is trimmable down to a dimension that would fit into the original silicone rubber filter base. (After a surgical removal of the old filter guts.) A couple small sheet metal screws with washers could hold the assy together.

The K&N filter has about 105 sq inches versus the Yanmar at about 95 sq inches.
We'll see how boring my winter gets.

Does the filter have the side hose connection? I can't tell from the pictures.
 
No it doesn't have the blowby connection.
That is the issue.
My plan would be to surgically remove the old filter element and attach a fresh filter element to the old base with the blowby connection. Thus the custom (expensive) Yanmar filter would be converted to a more readily available and serviceable arrangement. Using either the washable K&N element at one third the cost or the single use Wix element at one tenth the cost.

In the meantime another Tugnut has offered me a new filter at a bargain price.
He also pointed out that the same Yanmar filter is used on 4BY and 6BY engines.
That fact alone makes the filter area calculation in my original post less important. We could probably find a slightly smaller filter for our 4BY use.
 
Let us know how it works out. A point to be aware of. When I purchased my boat ( 9 years ago) I also ordered a spare air filter not knowing they were serviceable. Last year my original filter had to be replaced because the rubber portion where it attaches failed. Basically the part that clamps onto the turbo was split. No problem, I installed the new one. Well, about a month later it split. I bought a new one and it has been fine since. I suspect age may have something to do with it.
 
I just replaced the air filter on my 4BY2 150 hp engine. The old filter was splitting at the base where it attaches to the engine. That filter had lasted 10 years with cleaning every 2 or3 years. The price of the new filter was $260 Canadian. Given the longevity of the old filter I figure the price is OK. 🙂
 
Oh by the way (I should have posted this a couple days ago.)

We found out that the 6BY2 and the 4BY2 use DIFFERENT filters. The difference is due to the size of the turbo inlet. The 6BY is an inch or so larger in diameter than the 4BY.

Thanks to KBHARDER !
A good man.
 
Following this with interest!
We have the 4BY2-180 in our R25sc and wanted to change the air filter, but the dealer kept telling us just to clean it. I bought the K&N kit but not happy with the results. Its just not possible to get it really clean in the pleats. I worry about restricted airflow reducing our fuel mileage and impacting engine temperature and efficiency. So, I finally broke down and told the dealer to just send me a new one.
OUCH!
$335.00 Canadian! For an air filter!
We definitely need a better solution!
 
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