Cleaning foam filters with petrol
 

ive a dr 650 fitted with a twin filter and have got sick of carrying turpentine with me to clean it. Ive been warned off using petrol as it degrades the foam, others say its ok...

If youve been cleaning yours with petrol, has it been happy with it or has it swollen and become unusable???

thx Tim

Hey Tim. My bike has a foam filter which I cleaned with water. The reason being I was told that the foam holds special filter oil that absorbs all the crap that gets sucked in. Water was the least powerful solvent I had at hand so I went with that. I would worry about petrol as it may displace the oil. You can buy specialist foam cleaner but you say you dont want to keep carrying round bottles of cleaner which I can totally sympathise with! Id check whether your filter is one that holds oil, if so I dont think petrol is a good idea mate.

Hope this helps,
James.

Think this through for a minute.
The airfilter sits near the carburetor and is always exposed to a certain amount of gasoline fumes blowing back with the pulsing air coming back from the piston before intake valve closes completely and when you shut down the engine. Ergo, it is illogical that foam air filter material cannot withstand gasoline for a short time or the fumes thereof for extended periods.Filter foam will over time degrade from heat and chemical action .
Kerosene is simply a less volatile petroleum fraction.

The reason that gasoline is not recommended is purely as a SAFETY precaution. Gasoline fumes are highly flamable.Soaking your hands in gasoline is not good for their complection nor your health..
Any inadvertant spark in your work area could ignite it and the flash fire could severely burn you if your hands and clothing are drenched in gasoline , and you may well burn your bike, your garage and your house and yourself to the ground. And motorcycle companies do not like the prospect of sombody or their estate sueing them for the replacement of same and funeral costs.
This is why all motorcycle maintenance manuals state expicitly that air filters and other greasy parts should only be cleaned with a low flashpoint solvent, preferrably one which is non-combustible.
You can buy commercial degreasing solutions which fit this bill or you can use water and a strong detergent which can accomplish the task with more work.

That being said, gasoline makes a very good solvent for cleaning air filters.I do so on occasion when cleaning my KLR filter , which it is suggested in the manual be replaced after five cleanings anyway.
JUST BE ABSOLUTELY AND UNMISTIKABLY CLEAR THAT YOU ARE RESPONSIBLE TO KEEP THE CLEANING OPERATION WELL AWAY FROM ANY WORKSHOP AREA, NOT NEAR ANY POTENTIAL SOURCE OF SPARKS.Not indoors with a furnace which might kick in , or has a gas pilot light constantly on. Not near your motorcycle with hot exhaust or with the key still in the ignition which when turned could release a sparkplug's spark.Not near anybody who is smoking a cigarette, cigar, pipe ,hookah ..or playing with butane lighters, welding, toasters , bug zappers ...etc etc
Do it out in the middle of a gravel driveway,in the open air First remove as much of the caked on outside dirt as you possibly can .Use a small container to hold the dirty filter, pour on a small amount of gasoline swill it around and sueeze out the dirty oily mess. Dispose of the dirty gasoline , wipe alldirt and grit out of the comtainer and repeat the process several times until the filter is clean. Less than a liter of gasoline will do the job. . Last step, use an air hose to blow as gently as possible on the inside surface of the filter to dry it and remove any remaing surface grit toward the outside and thoroughly shake the dry filter out.
Apply the chosen oil to the filter, 10W30 says KLR manual, but if you use someting else fine. Water soluble filter spray is available I think and that would make cleaning with water and soap the simple safe approach.
Just BE CAREFULL if using gasoline.

There's absolutely no problem cleaning foam filters in petrol just make sure the filter is dry before you apply the oil. It doesn't damage the filter, In the summer I clean my filters after every ride, they must have been cleaned hundreds of times and are still fine.

Common sense evades me, I evade common sense.
 

Ok my bad, thanks for the save Sjoerd. I think another reason I didnt use petrol is becasue I didnt have spare filter oil.

I've used dish soap and water, heavy on the soap. No point in removing all the oil, just the dirt, and then let it dry in the sun for a few hours.