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I am considering removing the plenum/airbox and putting aftermarket foam air filters on my latest ride (HONDA CBX550F). I put some on my last bike and they worked well, however I used K&N filter oil and it ended up leaking out of the foam due to gravity and airflow. What sort of oil should I use to impregnate these foam filters? What is the saturation point and what does it look like? I wonder if I overloaded the filters to begin with, yet most of the oil apeared to be gone after about 500 miles.

im pretty sure youre not sure youre not supposed to put oil on foam filters.

I thought they didn't require oil either yet the instuctions mentioned that they needed to be oiled-- they didn't say with what so I used the K&N. It probably doesn't matter? I would hate to mess anything up. Come to think of it, conventional air filters require no oil but they are more restrictive. The foam allows alot of air through... similar to K&N. I thought of using transmission fluid to lightly coat the foam. Would this be a poor choice? What to do?!

no you wouldnt want to use atf, haha..much too thick. the k&n filter oil is very light. its designed to be just enough to help catch the debris passing through. atf would block most airflow as well, its really thick stuff by comparison. if it says it needs to be oiled, yeah, im sure the k&n filter oil would work just fine, if not better than some other brand.

Lots of misinformation floating around here.....

K&N's DO need to be oiled. With K&N filter oil only. You can't use foam filter oil on them, it is too thick. K&N sells a kit with the proper cleaning agent and correct oil as well as instructions on how to use both. It is the only way to correctly maintain a K&N filter. If oil is dripping off the filter when your done, it is severly over-oiled.

Foam filters MUST be oiled, with foam filter oil only. It is a different type of oil compared to the K&N stuff, it has a high solvent content and comes out of the bottle very runny. This is so you can saturate the foam completely while it is thin and runny, but don't over saturate it, or your bike will starve for air and run rich. Then it has to sit for a day or so while all the solvent evaporates. It will then be sticky and stringy and make a mess of anything it touches. Installing it is a messy job, lot's of people wear rubber gloves for this, I never bothered, my hands are ussually dirty anyway. If you put the filter on the bike before the solvents have evaporated, it cleans up easier, but DON'T run the bike for a day. The solvents will become extra fuel for your engine, causeing a dangerously lean condition. You can meltdown a motor doing this.

After the filter is 'dry' and set-up, the bike can sometimes be hard to start the first time. If it is, this is a sign you used too much oil, and the motor has to suck the excess out of the tiny passages in the filter before it can get enough air to run. Foam filter oil will always have dye in too, use something blue, it is much easier to see than the reddish orange(Motul) stuff. It is dyed so you can see it in the filter when applying, make sure the entire filter is impregnated with oil, but not soaked.

ATF is made for automatic cage transmissions and that's about all it's good for. Yes.... we used to use it for fork oil in '70's damper rod forks sometimes, some old guys swear it all you should use on the felt lube wick in breaker-piont ignitions, and you can soak the foam lining in your micrometer cases with it to keep them from rusting..... but chances are, if they make a specific oil for any given task, it will be a damsight better than ATF for that task.

'lots' seems a tad exaggerated.

ive really never dealt with any other filters other than the standard paper filters..i only know k&n's need to be oiled because i know several ppl who have them and say thats part of their upkeep. i never would have thought a foam filter would need oil...thats really weird. and moreso that theres a specific oil for it.

eh, so i was off about the oil to use for the foam filter. oh well.

[quote="txbadboy"]'lots' seems a tad exaggerated.
quote]

Understated if anything.

Oil is the only thing that traps dirt smaller than gravel in an air filter. A K&N or foam filter is as effective as an old sock over the intake without oil. I consider piston, ring and cylinder protection fairly critical and any incorrect information related to that end as 'lots'. Lots too much....

BuzZz wrote:Oil is the only thing that traps dirt smaller than gravel in an air filter. A K&N or foam filter is as effective as an old sock over the intake without oil. I consider piston, ring and cylinder protection fairly critical and any incorrect information related to that end as 'lots'. Lots too much....

I'll second that.

Thanks guys!

Is there a particular brand of foam filter oil out there that I should look for? I don't remember seeing a K&N product for that. It makes sense that it should be more sticky since the foam material is synthetic and just like a sponge. So that is why the K&N dripped off the filter!

I got the filters off JC Whitney yet they didn't seem to suggest any oil product to go with them. Very indicative of the way they sell stuff. They are vague at best.

but...oil is not the only thing that keeps anything smaller than gravel out. thats why theres always quite a bit of dirt on my paper elements. and the reference to the old sock and an oil-less k&n...well i really dont know, as ive never used one, or a foam filter. but i would imagine thats a bit exaggerated. my only point was that i went with my best guess, as i was one of the few that was online and in that section of the forum at the time. the reason people are here is to try to help others as best they can, not if they are necessarily 100% right. at least, thats my understanding of it. im hoping that there was no clear intention of someone trying to insult my intelligence through exaggeration of information simply to make sharper contrast on my information that has obviously been proven wrong. so point in fact...i was only trying to help. theres no need to get catty.