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If someone has either one, I would love to hear how the fit and finish is.
 

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Anyone know if you need a tune if you install a K&N filter and slip on? Or is it safe to run without tune?
 

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My take is very simple. WHY ARE YOU CHANGING THE FILTER?

There are many reasons why mfrs use paper. Efficiency is high on the list.

I can think of 100's of dealers whose mechanics dread filter changes and dealers who'd rather not have to carry the stock. But mfrs stay with paper.

Access to the 790D filter is a joy - So a change is not for ease of maintenance.

ime: Of many years

K&N's (and similar) need cleaning and re-oiling far more often than most folk do to maintain their efficiency - They clog up basically. and fast. many many after market filters gut stuck in because the blighter is a swine to get at. Think they get cleaned regularly?.

Foam filters MUST BE multi layered (varying pore size) and are better when treated with a proper goo (not oil perse). They do take longer to clog up as they have much great filer surface area (esp thicker foam ones). But are really messy to clean properly. I have a RamAir on my Triumph (maintenance as it eliminates a whole mass of tubing) and it takes a good hour to clean and retreat correctly. You need to massage the solvent and goo in to get it homogeneous. Anybody who says it's not required - is delusional.

Flters need to be cleaned from inside out and retreated from outside in. Period.

MRW say remapping recommend on KTM. Which is as we know a bit of a task. They however make one or two "only we" claims that are frankly not true.

Bottom line - I don't believe there will be a performance gain . I'll be sticking with Paper on the 790.

The only reason I can see not to is LONG TERM filter replacement costs. 30€ a year?
 

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Great response , thank you. My reasoning for changing the air filter is based on cost. A new paper filter costs $60aud which is roughly the price I can get a K&N for. I figured it might be cheaper in the long run and supposedly better performance?
 

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The reusable, cleanable filter is thought to save money, but considering the price and the number of kilometers that we keep our motorcycles, that's wrong. For performance, apart from making noise in the air box and it is not unpleasant, if you oil the filter too much after washing it becomes less efficient than a paper filter ... I have experienced this on a sports car.
I had them on all my motorcycles, and I don't think I'll ever put them back
 

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I like paper filters too. With the reusable filters it's too easy to under-oil them which allows excessive particulates into the engine, or over-oil them and make a mess in the intake tract and potentially foul air sensors.
 
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