K&N flame arrestor

[NateDogg]

Has anyone installed a K&N replacement flame arrestor on their engine(s)?

What is the normal life expectancy for a flame arrestor?

Mine is looking pretty sad.

 

[Lazy Daze]

Newer engines come with this (I think it's a K&N brand, anyway).

Or:

You can straighten the fins with a small screwdriver (or similar), clean the fins with Brake Cleaner and save your money.

On edit: Although, I suppose it never hurts to have extra filtration - just not sure it's entirely needed. I don't boat in dusty conditions, you know?

 

[Nehalennia]

Normally the flame arrestors are Aluminum and when the get clogged they can simply be cleaned. If they corroded and cannot be cleaned you can replace it. The K&N product looks good but I've never had experience with it.

 

[fc3]

I have K&Ns on Just Ducky's mains. The metal back flame arrestors would clog with dog fur and I was always cleaning them. The K&Ns do much better. I can just vacuum them off. Don't get much dust in the engine room, so have not yet needed to clean them. Think they'll last forever.

Best regards,
Frank

 

[Tail Chaser 661]

My 5 yr old KN filter is in perfect shape.

 

[capz]

I always wondered how the flame arrestor, with only vertical fins, filtered anything but very large particles. From what I've heard and read over the years about K&N filters is you have to oil them properly. Too little oil and you get little filtration. Too much you risk damaging sensors. Then again, anything would filter better than the stock flame arrestor.

 

[fc3]

K&Ns are easy to maintain. http://www.knfilters.com/cleaning.htm

 

[gruz1]

Would using a K and N filter increase my performance over a stock flame arrestor.

 

[capz]

Performance? I say no way. But no doubt it's healthier for your engine.

 

[patchkit123]

I used K&N air filters for year on my racing go kart engines. Oiled on dirt tracks and not oiled on pavement. You couldn't get any better. The flow bench showed lower air flow when oiled, but not much. My car mechanic friends tell my they are fine in cars and trucks just be careful when oiling. Like capz said you can damage the mass air flow sensor. I don't know if boat engines have these type of sensors. I would think they would. I would run them with little or no oil on a boat engine.

 

[capz]

K&N gives their end sellers a demonstration display, showing air flowing through their filter and a stock filter next to it. Above them are lottery balls bouncing around. The K&N visibly shows more air flow. I don't know if it was oiled. Better air flow SHOULD lead to better performance, although I've seen controlled tests online that showed it made no difference from stock. Even if it did offer better performance, does it also offer equal filtration as well? I don't think the benefits outweigh the risk of improperly oiling it.

 

[gruz1]

When I was looking at k and n filters, I came across the unconstrictor flame arrestor. It looks like a stock filter only twice the size. I think maybe I will try that, first thing though I cleaned my stock arrestor and will see how that works. I don't think it was ever cleaned.

 

[Lazy Daze]

K&N gives their end sellers a demonstration display, showing air flowing through their filter and a stock filter next to it. Above them are lottery balls bouncing around. The K&N visibly shows more air flow. I don't know if it was oiled. Better air flow SHOULD lead to better performance, although I've seen controlled tests online that showed it made no difference from stock. Even if it did offer better performance, does it also offer equal filtration as well? I don't think the benefits outweigh the risk of improperly oiling it.

If the filter was a reddish color, it was oiled. But that's dealing with a comparison between it and automotive filters. And, yes, certainly increased air flow can equal better performance, but you need to get the air out better, too. By the way, there are better filters out there than K&N - flow more and trap more dirt, too.

But, back to the boat side of things. We are now comparing a filter (K&N) to a flame arrestor. I would think the flame arrestor would flow better since it's more open than the K&N. basically, air has a straight, unrestricted shot right in. However, as mentioned above, the downfall is that larger particles of dirt will get in, too.

Being that a boat engine is typically not driven over dirty, dusty roads, that isn't much of a problem. Unless, your bilge is allowed to get dirty or, as mentioned, there's a dog involved. I just cleaned the arrestor for my dad about three days ago - same thing - covered in hair. I wonder how much went through?

Cleaning flame arrestors are part of normal maintenance. From what I've read (someone correct me if I'm wrong), your boat won't pass a Coast Guard test if they wipe their finger along the arrestor and it shows black. And those of you that do clean your arrestor know how quickly they turn black. Thanks, EGR. :smt101

Cleaning involves more than just wiping it off. Take it off, spray it with brake cleaner (or similar) from the INSIDE. Rinse with a hose from the INSIDE.

 

[capz]

Yes it should definitely be a once or twice a year job. I find it takes two brake cleaner flushes. When you take it off hold it up to a bright light before and after cleaning. You'll see a big difference. As I do have a dog, and I'm always brushing dog hair off the arrestor, I might look into something better. Not K&N, I'll pass on the oiling.

 

[Lazy Daze]

I have a K&N in my truck. Granted, it's a bit more work to oil it, but it really isn't all that hard. The oil comes in a spray bottle. My truck filter is a cylinder-shape, 12" long and about 8" wide. My fingers get a little tired of pumping the spray bottle. But the amount of filter material on top of a boat engine is miniscule compared to my truck. Just an observation.