Honda Motorcycles - FireBlades.org banner

1 - 20 of 28 Posts

·
Registered
Joined
·
201 Posts
Discussion Starter #1
hi lads, took off the tank to have a look at the airfilter, when i opened the airbox there was milky looking oil and water mixture to the front of the airbox, any ideas what this is and a cause, thanks
 

·
Registered
Joined
·
316 Posts
If u notice th hose is probably running from th top of th engine to th air box. It's a breathing system, plus it forces any excess exhaust that didn't make it out of th chamber to b sucked back into th chamber for combustion. An emissions system. My guess is ur oil level is above normal hence y u see th oil in ur air box. It's actually normal. I had an 06 Suzuki that had a similar set up but there was a sponge thing that caught th oil on its way to th air box.
 

·
Registered
Joined
·
3,226 Posts
Is it a K&N or other oiled cotton gauze type air filter? If so you could have gotten water in your airbox and you're seeing the mixture of water and oil from the filter.
 

·
Super Moderator
Joined
·
32,034 Posts
plus it forces any excess exhaust that didn't make it out of th chamber to b sucked back into th chamber for combustion.

Ummm...say what?
Never heard or seen this before.
How would exhaust gas get into the airbox?
 

·
Super Moderator
Joined
·
32,034 Posts
hi lads, took off the tank to have a look at the airfilter, when i opened the airbox there was milky looking oil and water mixture to the front of the airbox, any ideas what this is and a cause, thanks

The oil is just probably normal residue from the crankcase breather.
The water is most likely from rain or washing water getting in via the intakes. Clean it out and check it again next time you replace the filter.
 

·
Registered
Joined
·
201 Posts
Discussion Starter #10
hey lads, yes its a k&n air filter, the oil in the casing looks really clean and fresh,i syringed out a bit to have a look, there is a bit of a miss when accelerating hard, power is ok then a slight blip then back on power, had a zzr a few years back that done the same but it was caused by a single exhaust conversion, only have the bike a few months, i checked the plugs and they seem fine, iridium long life plugs. could the miss and the milky oil be related, the bike's temp is fine no overheating probs
 

·
Registered
Joined
·
240 Posts
If u notice th hose is probably running from th top of th engine to th air box. It's a breathing system, plus it forces any excess exhaust that didn't make it out of th chamber to b sucked back into th chamber for combustion. An emissions system. My guess is ur oil level is above normal hence y u see th oil in ur air box. It's actually normal. I had an 06 Suzuki that had a similar set up but there was a sponge thing that caught th oil on its way to th air box.
:plus1:

Overfilled my Gixer got the same result!

Plus loads of smoke and got black flagged :mad:
 

·
Registered
Joined
·
316 Posts
Ummm...say what?
Never heard or seen this before.
How would exhaust gas get into the airbox?
Page 1-40 of th Honda service manual. Under 'Crankcase Emission Control System' - "Blow-by gas is returned to the combustion chamber through the air cleaner and throttle body."
 

·
Super Moderator
Joined
·
32,034 Posts
Page 1-40 of th Honda service manual. Under 'Crankcase Emission Control System' - "Blow-by gas is returned to the combustion chamber through the air cleaner and throttle body."

That is crankcase pressure, not exhaust gas.
 

·
Registered
Joined
·
316 Posts
That is crankcase pressure, not exhaust gas.
I understand what ur saying cuz its a closed Crankcase system but that's to prevent Crankcase emissions from escaping into th atmosphere. And th combustion process produces these emissions which is carbon monoxide & hydrocarbons also called exhaust gasses. It's all on page 1-40 of th manual.
 

·
Super Moderator
Joined
·
32,034 Posts
I understand what ur saying cuz its a closed Crankcase system but that's to prevent Crankcase emissions from escaping into th atmosphere. And th combustion process produces these emissions which is carbon monoxide & hydrocarbons also called exhaust gasses. It's all on page 1-40 of th manual.

Yes, it is the gas that is forced past the rings and into the crankcase during combustion. But it is not really correct to say it's gas that didn't make it out of the combustion chamber. I don't think anybody would consider it to be "exhaust gas" as such. The emissions from within the crankcase are more oil mist than anything else.
 

·
Registered
Joined
·
240 Posts
Hopefully the products of the combustion process all escape out of the exhaust valve and not past the pistons!

However the pressure pulses from the pistons rising and falling and hot oil etc can be relieved via the breathing pipe.

Now if you are a numpty like me and overfill the oil, then the higher level causes the oil to be thashed up and, if high enough, some will go up the breather pipe and be sucked back into the engine a burn! :thumbd:
 

·
Registered
Joined
·
316 Posts
Yes, it is the gas that is forced past the rings and into the crankcase during combustion. But it is not really correct to say it's gas that didn't make it out of the combustion chamber. I don't think anybody would consider it be "exhaust gas" as such. The emissions from within the crankcase are more oil mist than anything else.
I agree but th manual specifically calls it "blow-by gas." So I'm not incorrect by saying "exhaust gasses" only cause emissions are produced by th combustion process and th combustion process produces exhaust gasses. Yes I should have used "emissions" or "blow-by gas" as a description initially but potato/potatoe.

My PAIR valve was disabled when I got th bike. Could it b cuz I have full aftermarket exhaust?
 

·
Registered
Joined
·
316 Posts
Hopefully the products of the combustion process all escape out of the exhaust valve and not past the pistons!

However the pressure pulses from the pistons rising and falling and hot oil etc can be relieved via the breathing pipe.

Now if you are a numpty like me and overfill the oil, then the higher level causes the oil to be thashed up and, if high enough, some will go up the breather pipe and be sucked back into the engine a burn! :thumbd:
+1

I over fill mine too most of th time but not by much. It's good to check th airbox regularly for jus that.
 
1 - 20 of 28 Posts
Top