Rotax / K&N Air Filter Deterioration

Short answer NO!

I had the conical K&N's on my last aircraft (20 years old), starting to look a bit the worse for wear, mainly from handling accidents. Splashed out and purchased new ones but kept the old in reserve.

When using the K&N air filter too many people use the wrong chemicals to clean it which causes EARLY deterioration of the gauze. Just use either the K&N cleaner or something like "Oil Eater" or "Simple Green" cleaners that are water based and biodegradable. You don't want to use gasoline or corrosive solvents. Even though these filters will last a long time after many years of service they are a consumable item. Like many things we come in contact with,,,use it don't abuse it. This way we have less maint. and get to keep more of our money. :) 

p.s.

I use Oil Eater. It's water based and biodegradable. I've been using it for almost 20 years. It doesn't hurt anything, but it does a great job on wiping up grease and oil I use it on aircraft bottoms for oily residue, air filters, oil on the floor, grease on the stove top hood at home and grease on the stove. It wipes stuff away without any effort. I take K&N air filters and put them in a huge (old pretzel) plastic jug. Add the Oil Eater and some warm water and swish it around. Bugs and oil disappear and then I let it dry. In 20 years this method has never damaged a filter.

Rotax Minute - K&N Air Filter Servicing

https://www.rotax-owner.com/en/videos-topmenu/rotax-minute/380-2-oil-inj247

After 17 years of service that filter has paid for itself,no shame for buying a new one. Nothing lasts forever.

My biggest problem with the K&N filters is that when they get about 4-5 years old the rubber sleeve that slips over and clamps to the carb gets very stiff and seems to shrink, so it gets very difficult to get it back on after cleaning without distorting the pleats from the hard pushing. I replace mine for this reason.