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Discussion Starter #1
I changed my air filter at 11500km today (third service).

I expected to see a dusty filter, but not this:




The thing had OIL over most of it's surface. Barely a fourth of the filter was allowing air through - the rest was caked with this grunge. It was so badly saturated with oil that even the bubble wrap packing that I took it back in had oil on it at the end of my trip back.






This was not the only filter that looked like this . There was another on the ground nearby, obviously taken off somebody else's bike and it looked much the same. Clearly, there is a design defect out here. The breather is supposed to throw the oily crankcase blowby downstream of the filter towards the engine - clearly, this is not happening.

To think that I was testing the taller gearing with this filter on the bike! I think I'll route the breather tube onto the chain, the paper element doesn't need the lubrication.
 

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Actually, the photo isn't unusual for a small-engine bike that has been ridden hard; both of my bikes will do that. High rpms vaporize oil and the breather hose removes vapor. My 230L air filter gets changed every 3K miles or so.
 

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Pfft.. not even broken in yet :D

Seriously, do the math. 250cc @ 5000rpm requires 125000cc's of filtered air. Sounds like a lot.. convert that to cu.ft/min = 4.5

Oops.. made a mistake there. you bike only inhales every 4th stroke. So divide that by 4. So a little over 1cu.ft/min at 5000rpm.
 

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From the users manual: replace Air Cleaner (aka-air filter) every 18,000 MILES or service more frequently when riding in unusually wet or dusty areas.
That air filter pic looks awful dirty for just over 7,000 miles on it...I'll have to take a gander at mine tho im just at 4K so far
 

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Discussion Starter #8
is that the inside part of the filter? the side thats not exposed to the outside dirt and crap? if so thats very odd.
This is the side exposed to the outside. Normally the breather opens downstream of the filter, after going through a small coalescer if possible.

Actually, the photo isn't unusual for a small-engine bike that has been ridden hard; both of my bikes will do that. High rpms vaporize oil and the breather hose removes vapor. My 230L air filter gets changed every 3K miles or so.
The filter not particularly DUSTY, just has oil over it. While singles throwing oil out of the breather is not in the least unusual (owing to the big variation in crankcase volume twice during each cycle), having it wind up on the air filter on the intake side certainly is.
 

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I've got a little over 7,600 miles and mine is beautiful. I don't think I will have to replace mine at 16,000 miles at this rate. I rode in a desert environment this summer for two months and a rainy and wet environment now. I think something is wrong with your bike.
 

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I saw my airfilter after being changed at a 6000km interval service. Looked nothing like that. No trace of oil, just a bit of dust.
 

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Discussion Starter #11
This air filter has never been removed before.

Wrong assembly? By Honda?

Lets see what they have to say.
 

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I love all these threads trying to pic one single fault with our cheap affordable Thai made comuter bike with sporting abilities :D.. everything from sidestands to fuel filler caps lol.

We can thrash it trash it.. and it still wont fail... Just get a new $20 filter.. sorted.
 

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I love all these threads trying to pic one single fault with our cheap affordable Thai made comuter bike with sporting abilities :D.. everything from sidestands to fuel filler caps lol.

We can thrash it trash it.. and it still wont fail... Just get a new $20 filter.. sorted.
Lol, agree'd, so many people whining and bitching about it. I bought it as a first bike, to save gas, and need little maintenance. So far it's done exactly that!
 

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Discussion Starter #16
Lol, agree'd, so many people whining and bitching about it.
Lol, we must not share any problems that we have since the whining and bitching disturbs ****** who have not faced problems so far, and are sure they will never face any sort of problem down the road.
 

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ok..so if every thread and every post was simply about how much we love it just as it is....most of us wouldn't even bother to log on here anymore....right? right? you know i am

to err is human...but to Bi#ch and complain is just as human.....obviously that filter is covered in oil for a reason when most other people have clean ones..i dont think its over the top in any way shape or form to start a thread about it with pics...looks like someone thought it needed to be coated in oil prior to installation like you do a riding mower air filter?!

dont know why people are whining about people posting problems they may or may not have..especially in the "Problems and issues" forum at that..that is exactly what its here for... if you dont like it go log into cbr250.org and see if they whine and moan any less....
 

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arn, knowing what has been posted on this thread, I would think this was the scenario. Just a guess so you can take it for what it is worth, no need for a nasty remark.
It looks like you ride in some dusty conditions, probably fairly severe. Lots of dirt in that filter for such low mileage.
Assuming the conditions cause the accumulation of dirt (not sure what else could be the cause), the restriction imposed by the dirt would cause the crankcase ventilation system to back up enough to allow oil vapor to condense on the air filter.
This seems to me like to most possible rational explanation of what occurred based on the evidence present.
I have not looked at mine, but I would bet it's practically spotless. Another factor could be if you ride in rain a lot and the filter got saturated with water on several occasions or even regularly.
Another factor could be if you ride close enough to other vehicles that your filter got a lot of dirt on it due to the vehicles in front of you kicking it up off the road. You can tell a tailgaters car by the paint chips and windshield chips that are much more numerous than typical cars, as well as prematurely plugged air filters.
All or any of these assumptions could be true or not, only you know the answer to that.
Just on observation on my part, no need for the typical forum attacks, it wont change 45 years of experience and 30 years of working on vehicles.

regards
Badger
 

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Discussion Starter #20
arn, knowing what has been posted on this thread, I would think this was the scenario. Just a guess so you can take it for what it is worth, no need for a nasty remark.
It looks like you ride in some dusty conditions, probably fairly severe. Lots of dirt in that filter for such low mileage.
Assuming the conditions cause the accumulation of dirt (not sure what else could be the cause), the restriction imposed by the dirt would cause the crankcase ventilation system to back up enough to allow oil vapor to condense on the air filter.
This seems to me like to most possible rational explanation of what occurred based on the evidence present.
I have not looked at mine, but I would bet it's practically spotless. Another factor could be if you ride in rain a lot and the filter got saturated with water on several occasions or even regularly.
Another factor could be if you ride close enough to other vehicles that your filter got a lot of dirt on it due to the vehicles in front of you kicking it up off the road. You can tell a tailgaters car by the paint chips and windshield chips that are much more numerous than typical cars, as well as prematurely plugged air filters.
All or any of these assumptions could be true or not, only you know the answer to that.
Just on observation on my part, no need for the typical forum attacks, it wont change 45 years of experience and 30 years of working on vehicles.

regards
Badger
Thanks for taking out the time to analyse it :)

You might notice the nasty remarks are only for forum trolls who add no value, don't bother to analyse what the problem might possibly be but are quick to come up with mean minded smart ass comments (or are paid by somebody to be as obnoxious as possible to those who point out concerns with the bike, valid or otherwise).

I'll give an idea as to the running my bike has had. It's been fast highway running for almost 7-8000km, with cruise speeds of about 110kph where possibly, the rest being comparatively sedate city running. For those who have been to India the speeds may sound high, but they are definitely do able on the main highways, especially at night when the jaywalkers, cyclists, odd villager who's strayed onto the highway have retired for the night.

India is dusty, no doubt about that, but the highways are not excessively so except in the few areas where there is construction work in progress. The "dust" on this filter is what I expected to see in any case, having a CRF 230 derived bike which has a very similar paper element, it's the oil that's the surprise. The CRF engine also throws oil into the box via the breather but that is downstream of the filter. This year there has been very little riding in the rains, mainly on account of a back problem, so it's a little unlikely that the water could have got sucked into the element, especially given that the inlet is tucked away under the seat, and is not like a ram air intake, for example.

As regards riding close, yes, that's how it is in traffic here, but all of it is at low speeds in the city, not much crud being thrown up.

I might have been inclined to think more in terms of an assembly or bike specific issue, but for the fact that nobody AFAIK had taken the filter out (I prefer to hang around while the service is done) and there was that other filter at the service centre with very similar oil stains on it, and it was also in for the 12000km service, having returned from a tour of North East India.

This (dirty) side of the filter is in any case the outside, where the breather should not be sending any oil at all, and the throttle body side does not have any oil on it (just a bit dusty, within normal limits). I guess the service centre might receive some reply from Honda, I'll communicate with them sometime next week
 
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