How Dirty is Air Filter for Change?

Hey guys,

Please have a look at the pics and give me your opinion on the state of my air filter.

Is this in need of changing/cleaning?

Would You?

Info:

June 29th: Last filter clean and change was 2 rides ago. super 60-90 degrees. All dirt.

July 29th: Dual Sport ride 50miles asphalt, 24miles trail.

(yeah baby! Gifford Pinchot Boundary Trail#1 - #2 Summit Prairie out of Troutlake, WA!!!!)

 

I broke the seal and took pics, looks perfect. My only worry is breathability at this point.

It has never had a single burp while running. (besides my own stalls, trying to go fast up steep shit and gunning too much for quick start button grinding, in too tall of a gear with not enough clutch pull!!!!)

Just lazy riding?

Probably.

 

Anywho, what say you?

That amount of now sticky ass dirt affecting breathability of bike?

 

I have another ready to go but it's seems like, no wait.......

I just checked, I have one clean and ready for oil but not oiled.....

Well shit then.

 

Think I'm gonna go one more 4hr ride (hopefully all dirt) and then give her another look, plan on changing out. Cleaning it up again.

Whew.....I love working on my bike but not as much as riding it.

 

 

Sent from my SM-G955U using ThumperTalk mobile app

 

 

Man, it looks waaaayy dirtier in person.


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it takes seconds just change it out alot!

My dad and a bunch of old life long mechanics all say dirty filters filter better than clean ones. After years of being lazy and letting my filters get really dirty, I've still never had a spec of dust on any of my intake boots. Starting to agree with the old timers. Of course I've pretty much always run non biodegradable filter oils and not that crappy biodegradable stuff that is in a constant state of breakdown (as spud says) and lets moisture and water through.

 

Thanks Dan,
Well, I do run the NoToil green which is def stickier than red. It has no alcohol in it either.
I don't have problems with dirt filtering, I just start to worry about the engine breathing too hard. It's a big 4stroke so it pulls the air and hard to tell if it isn't getting all it needs.
The oil keeps out dirt, no problem. The dirt in the oil doesn't let air in.
Or well not as much.

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Thats not that bad, but I'd change it.......after all KTM seems to want to charge 5 figures for simple thumpers these days.

 

If you ride in a group, expect to eat (U and motor) a whole lot more dust.

I'd put another 10 hours on that filter. :ride:

that's a typical "used dirt bike"  most of us clean our air filter after every ride unless it was all pavement. why chance losing and engine over not maintaining something so simple and tool-less to service :thumsdown: to dirty filters

25 minutes ago, Airboss/oc said:

that's a typical "used dirt bike"  most of us clean our air filter after every ride unless it was all pavement. why chance losing and engine over not maintaining something so simple and tool-less to service :thumsdown: to dirty filters

Most of who?! I don't think so. :lol:

And a dirty air filter provides cleaner air than a fresh air filter (within reason). Biggest reason to clean it is air flow for performance.

36 minutes ago, Airboss/oc said:

that's a typical "used dirt bike"  most of us clean our air filter after every ride unless it was all pavement. why chance losing and engine over not maintaining something so simple and tool-less to service :thumsdown: to dirty filters

because his filter, the one in the picture, is actually better at stopping dirt than a freshly oiled one.

when in doubt, change it out   said you had another one?   don;t want it to get to the point of being restricted that when it starts trying to pull air around the rim or anywhere it can.   For the throttle just cracked riding your doing at gp it's probably fine, but if you hit a road and wfo it ?

filter oil has 2 parts, tackinees and oilness. If dirt soaks up the oil and all the tackiness is gone it's not a better filter.

20160702_134508.thumb.jpg.ea86d0d06d227b3f7a4e76b86e87e45a.jpg20160702_134520.jpg.afe24d139c907ceeaa46857d4eeebd64.jpg20160626_165456.jpg.626485fd13b7587107f4c73beb3f6b61.jpg20160626_140845.thumb.jpg.a935ce9e11f8ac0a1e61d051b69a49f3.jpg

Agree with you@highmarker.

@91kdx I also agree.

The bike seems to be working harder than on a freshly cleaned and oiled filter.

I'm gonna change it out.
But here it is early Saturday evening and I haven't done it yet.
I did start but I also am in the middle of replacing my taillight and resplicing that harness is a pita.
So, I'm gonna do it.
The filter had plenty of oil. The dirt it has trapped is super tacky like mud.
Nothing breathes in mud...........


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Old school:

Allow engine to cool overnight and remove spark plug

Turn engine to just before TDC assuring exhaust valve is closed

Press your lips firmly on the spark plug hole and suck as hard as you can, if you notice any restriction then its time to clean the filter.

Filters have lasted me many years between servicing and only once did I end up in the Hospital from a case of stuck floats

15 hours ago, LSHD said:

Most of who?! I don't think so. :lol:

And a dirty air filter provides cleaner air than a fresh air filter (within reason). Biggest reason to clean it is air flow for performance.

so the increased suction doesn't cause dirt to pass, that's BS. your theory is dirt helps filter the dirt ???? that's a dumb idea

3 hours ago, Airboss/oc said:

so the increased suction doesn't cause dirt to pass, that's BS. your theory is dirt helps filter the dirt ???? that's a dumb idea

Why not do some research before pretending to know something and calling other people dumb?

Look up "depth loading" and "cake formation" in foam filters. 

The trapped particle size goes down (better filtration) as the filter gets dirty. This is fine up until the point where most of the sticky surfaces are covered with trapped particles and air flow is reduced enough to affect performance. That's why I was very specific about dirt being fine within reason. My two points were that very few of "us" change filters every ride, and some dirt on a filter is not harmful. 

Edited by LSHD

I change airfilters about every 30 hours for dual sporting, just depends on the contamination level, then it could be lower.

Absolutely no performance difference clean or dirty, on my intervals.

Id say if you do see a performance difference, then you probably went too long.

 

The op picture , its not dirty enough to cause an issue.

Thanks for your input fellas!

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Thanks Dan,
Well, I do run the NoToil green which is def stickier than red. It has no alcohol in it either.
I don't have problems with dirt filtering, I just start to worry about the engine breathing too hard. It's a big 4stroke so it pulls the air and hard to tell if it isn't getting all it needs.
The oil keeps out dirt, no problem. The dirt in the oil doesn't let air in.
Or well not as much.

Sent from my SM-G955U using ThumperTalk mobile app



If you're motor isn't able to suck in enough air I don't think it's going to work harder. If anything I'd think that would make the motor run richer since there'd be more fuel than air. Slightly richer is bette than lean in my opinion.

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