Kawasaki KLR Forum banner

1 - 8 of 8 Posts

·
Administrator
Joined
·
8,250 Posts
Discussion Starter #1 (Edited)
Ready for some Wierd Science?

Here goes! You've heard Paul continually ask people if they have cleaned and properly oiled their air filters. Here's how and why.

These are three dirty filters, progressing left to right from "Not too dirty" to "Pretty damn dirty". The characteristic dark spot is on the side of the filter opposite the air filter door. That's the main incoming stream of air from the back of the airbox.


To clean them I took a half a pint of gas and put it in a container, then simply soaked and squeezed and soaked and squeezed until the filters were clean. I then did a final rinse with clean gas. This is what the half pint of gas looked like after I was done.


Inspect the filters for foam shredding, which indicates extreme age, and seam separation. This filter had some foam shred and a couple of seams were coming loose. This filter has had seam repairs in the past which were in good shape. I discarded this filter because the foam was degrading. It had seam separation, but the seams were not completely loose.


To oil the filters I put a couple of ounces of filter oil into a large Zip-Loc and kneaded the filter until it turned a uniform color. My filter oil, FFT, is blue. When it is properly kneaded in the filter turns a light green inside and out.



Now, just what is it that is being filtered? To find out I filtered the gas and poured what passed through the filters into a graduated cylinder. I set the cylinder and filters aside for three weeks so the filters could dry and the dirt in the gas could settle to the bottom of the cylinder. Here's what the cylinder looked like the day it was filled.


This is what it looked like three weeks later.


The stuff that is suspended in the gas is so fine that it won't settle out, except for a very small bit, as you can see in the bottom of the cylinder. It's not as much as it looks like; the bottom of the cylinder has a punt in it much like a wine bottle.


More to follow.
 

·
Administrator
Joined
·
8,250 Posts
Discussion Starter #2 (Edited)
Let's take a look at what was trapped in the filters.

Here is the paper filter after I had scraped the crud off of it and the scrapings of what was filtered out. The stuff is a very fine grit, quite like silt. It is pretty big stuff if you happen to be a piston ring.


It is not quite dry, sort of like it is held together with oil that won't evaporate, so it is pretty clumpy.


This is the stuff that passed through the filter and settled to the bottom of the cylinder. There's a dollop of it hanging upside down on the spatula. It is really fine stuff.


This is the dregs on the wall of the cylinder.


Think about this for a minute. The filters caught all of this stuff because of the oil that was in the filter. That oil caught stuff that was so fine that it passed through a paper filter and quite a bit of it wouldn't even come out of suspension in the gas used to clean the filter after being left alone for three weeks! That gas isn't green or blue, so it is not filter oil contaminating the gas. It is fine matter, probably silica (don't be impressed; I'm not that smart. Silica is some of the most common stuff on Earth, so it is a good bet). Do you know what the make grinding paste out of? Yeah, silicates.

From someone smart, The Tiny Little Woman Who Lives At My House And Hands Out Work (TLW for short). She's a biochemist who has, for the past several years, conducted studies into air particles in the LA basin. She's primarily concerned with the vapors, but has a working knowledge of the particulate side of air pollution. The particulate matter in air is largely comprised of carbon compounds, iron, copper, silica and diesel exhaust.

Without oil in the filter the only thing it might catch is the big stuff that would not pass through the paper filter. Maybe.

Listen to Paul. Oil yer damn filter reel gud.
 
  • Like
Reactions: roadrash83

·
Registered
Joined
·
6,642 Posts
Tom,
May I suggest that you take the tinyest sample of the finest particulate that you might gather off of the side of the beaker and attempt to measure it with a micrometer?

It is the talcum powder fine dust which can sneak past poorly serviced or past due for service air filters which is the most deadly to all internal combustion engines.

The big chunks are easy to prevent from infiltrating an engine!
 

·
Administrator
Joined
·
8,250 Posts
Discussion Starter #4
That's a pretty tall order for a handheld micrometer.

The proper tool for that is a measuring microscope.

Even though the material is probably hard, it is so small that the pressure from the mike's spindle and anvil would crush it, so even a P&W SuperMike is out. I used to have an early version of the P&W...

Also, the size of silt particles could simply read "0" on the handheld mike, as its resolution is .0001" and the smaller silt particles are right in that range.

But, of course, I'll try! It might be interesting to see if the particles from the filter are measurable.
 

·
Registered
Joined
·
109 Posts
Great post. There is no excuse for running a dirt air filter in any bike, Especially the KLR being that is so easy to get at to remove. I wish the rest of my bike where this easy.
 

·
Premium Member
Joined
·
2,903 Posts
Tom, Thanks for this; it reinforces what we've all been saying for years - proper filter prep and maintenance is critical. After years of offroad racing (and yes, at least one engine destroyed by dust....from a warped filter cage in my case), I've become very anal about filter mainenance. A 4 hour race in conditions so dusty that you can't see more than 10' in front of you really tests your filter's abilities! I've had filters so clogged in a matter of 1-2 hours that the bike won't run properly and we've had to change filters at the gas pit.....those filters make your "dirty" filter look very fresh indeed!

The KLR is even more sensitive to filter changes/cleanings because the filter is less than half the size of a real offroad bike....yet we often use them in conditions that are just as dusty and usually for longer periods of time/distances. On some trips I carry spare clean and oiled filters in zip lock bags for "on the road" swaps.

Cheers,
Dave
 

·
Registered
Joined
·
100 Posts
Nice post...cleaned filter last week. I like the colored oil.

I cleaned and re-oiled, cleaned and re-oiled, cleaned and re-oiled...

I'm running a Uni with that clean/oil system. Keep the oem on hand oiled as well.
 

·
Registered
Joined
·
6,642 Posts
Nice post...cleaned filter last week. I like the colored oil.
And I immediately have to ask, Did You Re-Oil yours?

Cleaned & Re-oiled, Cleaned & Re-oiled, Cleaned & Re-oiled,,,,,,,,,

With FOAM Air filter oil or even engine oil, but please don't use oil intended for the 'cotton gauze' type of air filters, its too thin.
Don't leave any doubt about it!!
Pretty Please.
 
1 - 8 of 8 Posts
Top