Air filter maintenance

[Shirou]

I'm a total n00b in bike maintenance. My bike is idling weird and I thought the air filter was clogged.

I was right

This is a K&N filter somebody installed which is high performance, high flow, blah, blah, blah and I don't care that much about. Performance parts on a 250 are pointless. Anyways, I went around looking for the K&N cleaning kit and nobody stocks it here so I got normal filter oil, this one:

I know I'm not supposed to clean and reuse a K&N with non K&N oil and cleaning agent. Again, I don't care about the K&N, I got the stock filter somewhere and I'm about to clean it and use that instead.
Now the problem is, I think this is not the right oil for the stock foam filter, doesn't say so in the label of the oil, it says it's for offroad motorcycles and ATV's and that kinda makes sense because I bought it from a retailer that sells mostly offroad stuff.
Here's the label:

The manual says nothing about what to use, it just says "clean the filter with high flashpoint solvent" and "use a high quality filter oil". Nothing else.
Is it ok to clean the foam filter with gas-oil (or Diesel, or Diesel Oil, I don't know the name everywhere around the world, that thing your truck runs on)?

 

[Trinith]

I don't think diesel fuel is a high flashpoint solvent. I believe that would be referring to something like MEK or turpentine or whatever. Assuming you actually have a foam filter, and not a paper one (which if the manual says it's foam it probable is) then the oil you bought will be fine. I think the off-road labeling is basically saying it's strong enough for off-road use, which generally means it will handle the rather light load put on it by on-road use.

 

[Shirou]

This is the stock filter

 

[CaptainCranky]

I would replace the filter - actually either filter. Starving an engine of air is a sure way to reduce it's lifetime dramatically.
You can clean foam only so many times and it will degenerate anyway, if left sitting around (exposed to heat change, rats peeing on it, sun or damp) the degeneration will happen quite quick.
For the huge sum of (what? around $20?) you can be more certain with a new filter.
BTW off road use = more dust = filter clogs sooner = heavier workload (for the filter).
If an additional problem is that you can't get a filter nearby, then maybe clean that foam one (the K&N looks like paper to me = cannot be cleaned...) and ride the bike to where you can get one, or until you can order one in

 

[Shirou]

I need the bike in about 6 hours to go work so my desperation won.
The service manual leaves too much to the imagination.

I cleaned the foam filter by submerging it in Diesel, then squeeze, replace the solvent, damp, squeeze, replace solvent, damp, foam, squeeze, throw away the solvent.
I then spread detergent/degreaser on the filter, dampened it on water, squeezed, replaced the water, and kept cleaning that way until there was no sand or any particle coming out of the filter and the water came clean.
I "dried" the filter on a centrifuge, squeezed on paper towels, they came dry so I applied the filter oil on all sides following the instructions on the can, left it to dry 30 minutes, squeezed the filter on a plastic bag so it'll saturate evenly then I squeezed it between paper towels to remove excess.
Now it's inside the bike, shame that I couldn't take it for a test run because it's raining.

The "high flashpoint solvent" is just a safety measure, it means that the solvent used shouldn't easily ignite by a spark or flame. Normal fuel will ignite easily and it spreads in the air as it evaporates, it has a low flash point. High flash point could be Kerosene or Diesel fuel. I used Diesel because it's cheaper and I have a can of expired Diesel I removed from the truck once because it was parked for months.

 

[CaptainCranky]

Sounds like you persevered and did well mate!
Score:
Shirou Rider - 1
Air Filter confusion - nil

 

[Shirou]

I recalled when my brother used to clean the filters on his dirtbikes. I never paid much attention or maybe it was because I was drowsy because he cleans everything with regular fuel and it impregnates the whole house.

So do you recommend replacing the element once in a while? I may add it to the cart next time I buy spares.

 

[CaptainCranky]

So do you recommend replacing the element once in a while? I may add it to the cart next time I buy spares.

Yeah I would mate - mostly because it's been off the bike and may be subject to degeneration, like most plastic based materials. Then you know what you're dealing with.

 

[CBRHoonigan]

my k&n panel filter requires to be covered in the cleaner till its covered completely
leave it for a few mins then gently rince off with water then leave to dry

 

[Shirou]

my k&n panel filter requires to be covered in the cleaner till its covered completely
leave it for a few mins then gently rince off with water then leave to dry

then apply the special K&N oil filter for cotton air filters. I know the procedure but I can't get my hands on the "Special" K&N products.
The cleaner and oil are K&N branded and they're near impossible to get here. For half the price I got a can of filter oil that I can use 3 times.

Also, I really don't trust the K&N filter, I think is less effective than the stock foam filter.

 

[Trinith]

K&N is only ever going to tell you to use their stuff because they don't know what is in other stuff. It's not because their products are the only ones that work. There's plenty of other things that will work fine for a K&N filter, but using their products keeps some of the culpability in their court. If they don't tell you to use their stuff, and you use nitromethanol and blow your engine to hell then you could (conceivably) hold them accountable for some of the damages.

As far as replacing goes.. You can generally clean foam filters a couple times before they start to deteriorate much. It's not a bad idea to keep a new one handy so you don't have to wait for one to show up if yours looks trashed, but you certainly don't have to replace it just because you already cleaned it once.

 

[CBRHoonigan]

ayeh i forgot to put about the oil the kit comes with both, but as im aware putoline and rockoil do eqiuivalent to these cleaners and oils, and no a stock paper filter is just cheap and shitty, A k&n or other aftermakrter panel filter is far superior lasts longer better made warranty for life ect, and you usually need them when you have exhaust systems on your bike otherwise it just knocks the air fuel ratio out of wack

 

[Trinith]

a stock paper filter is just cheap and shitty, A k&n or other aftermakrter panel filter is far superior lasts longer better made warranty for life ect, and you usually need them when you have exhaust systems on your bike otherwise it just knocks the air fuel ratio out of wack

K&N filters vary from bike to bike, and probably won't affect the AFR. Most bikes don't change their fuel mixture by looking at the exhaust gasses. Some do, but generally it's either got a carb (which never changes on its own) or it follows a pre-defined map that correlates the amount of fuel injected to the throttle position and current RPM count. K&N knows which bikes do which (usually) and shape the filter to suit. My VFR doesn't change its own fuel map, and the K&N filter sitting inside it has an opening about 1/3 the size of the stock filter, to restrict the airflow and keep the fuel mix in check.

You also don't -need- to change the air filter just because you put a new exhaust on. Yes, you're going to lose a little power if you only change the muffler, but changing the air filter isn't necessarily going to bring it back. You have to up the fuel flow as well, which means tuning the carb or re-mapping the ECM. If you don't do them both you're not going to see much gain, and in reality buying an exhaust system for more HP is a good way to spend a LOT of money for very little gain.

BTW - paper filters work fine, but for much shorter periods of time. The only reason I put a K&N on mine is that it saved me about $15 over replacing the stock one. Which reminds me, I need to go clean that thing..

 

[PistnRods]

I wouldn't over think it really. A lot of aftermarket stuff says "offroad only" as a legality to cover themselves in all states. It's just an air filter and K&N units are rather simple ones. The reason they are advertised to "breath" better is because the material is not woven as tightly together. That's why it needs oil to catch the smaller particles from going through while your stock one typically does not.

Just pour some soapy water on it an spray it out with a hose. Once dry, lightly apply oil and you're good to go until next year. It's important to only use a light layer oil...don't drench the thing. :lol:

 

[CBRHoonigan]

Doesnt change Air fuel ratio Yet allows more air in? honestly we proved this with my mates and my own bikes, 5 diff bikes dynoed before and after and it improved the afr on each bike some carb and some fuel injected