KTM LC4 Toilet Paper Filter

[DoubleWasp]

I picked up a KTM Duke converted to dirt duty, and I was preparing to do an oil change. First thing I learned is that doing an oil change on a dirtbike type motorcycle is more involved than doing my Harleys.

Second thing I learned is that this engine has a toilet paper filter as a secondary filter to the primary.

Is this really what I think it is? Is this a factory application of a toilet paper style bypass filter? I have to imagine that toilet paper filters pretty much have to have really good efficiency figures since they are some seriously tight packed media, but I could be wrong.

Anyone aware if efficiency figures have ever been released for these? I assume they must be significantly more efficient than the primary filter to be used at all.

 

[CT8]

A 1290 Duke?

 

[Ducked]

Don't understand that picture: Some oil on the inside and none elsewhere. How'd that happen?

You assemble it and then take it apart again before using?

 

[CT8]

Originally Posted By: Ducked
Don't understand that picture: Some oil on the inside and none elsewhere. How'd that happen?

You assemble it and then take it apart again before using?
That is the toilet paper element new and unused the center thing is part of the filter housing like a Frantz bypass oil filter

 

[CT8]

I looked up the model duh me!. I was looking a the 1290 a few weeks ago.

 

[DoubleWasp]

Sorry. It's a Duke 620, with the LC4 620 engine.

 

[CT8]

D.W. could you please explain the filter better. 50 + hp off road bikes are crazy my neighbor has a 500 CC 2 stroke Honda It is stupid fast.

 

[DoubleWasp]

Well, all I can explain is assumptions.

Usually a "toilet paper" filter is a very low-micron filter (1-2 microns absolute, sometimes sub-micron) that is used to filter a fluid to well below what a standard spin-on filter can do. That appears to be exactly what this is. This particular filter is filtering the oil that is being pumped directly at the piston pin, and back to the frame reservoir.