My vapors exit the air filter via a length of fuel line hose - which terminates beneath the bike about 1.5 - 2 inches below the frame rail. Nothing to check, nothing to clean; I'm a simple guy.
found this to be the best way...also drilled head breather bolts out a bit larger and went with 3/8 fuel line.i Also found plastic Ts are too restrictive....so full 3/8 brass....and the barbs grab so well the hose doesnt even need clamps...Under bike now for 20k .....the small stock lines would get clogged up with the wipped up oil and air ( white goo) Now we do all twinks and m8s this way.. filters always clogged and no real need for the,..
But no matter how you do it....it is a good mod. These cost a like 5 bucks and 45 mins with a step drill..and hidden
found this to be the best way...also drilled head breather bolts out a bit larger and went with 3/8 fuel line.i Also found plastic Ts are too restrictive....so full 3/8 brass....and the barbs grab so well the hose doesnt even need clamps...Under bike now for 20k .....the small stock lines would get clogged up with the wipped up oil and air ( white goo) Now we do all twinks and m8s this way.. filters always clogged and no real need for the,..
But no matter how you do it....it is a good mod. These cost a like 5 bucks and 45 mins with a step drill..and hidden
Bump that is a really clean setup. Thanks for sharing. Where did you route the hose down to?
just a curious observation / question..no concern whatsoever about those big fat tubes interfering with the intended design of the airflow...?? I mean they do appear to cover a decent percentage of the filter element, maybe completely insignificant or inconsequential....
While we're wondering, I've been wondering about the effect at the throttle body intake end of what I assume is a low-pressure atmosphere. In stock form, that little rubber hose comes from the two breather bolts and aims directly into the throttle body. When running, the engine is "sucking" air thru the filter, and also breathing through the little rubber hose. Is it reasonable to assume that the engineers calculated that low-pressure area to help the motor breathe? What might be the effect on breathing of taking the rubber hose out of the low-pressure region, maybe putting it outside the air-box, under the bike, and whatnot.?
While we're wondering, I've been wondering about the effect at the throttle body intake end of what I assume is a low-pressure atmosphere. In stock form, that little rubber hose comes from the two breather bolts and aims directly into the throttle body. When running, the engine is "sucking" air thru the filter, and also breathing through the little rubber hose. Is it reasonable to assume that the engineers calculated that low-pressure area to help the motor breathe? What might be the effect on breathing of taking the rubber hose out of the low-pressure region, maybe putting it outside the air-box, under the bike, and whatnot.?
The fluid dynamics are deceiving on this one.
The only "low pressure area" is behind the throttle plate on the engine side. All else is at atmospheric pressure. However, when the throttle is opened there is air velocity and that's what pulls the crankcase vapors into the engine. Blowby within the crankcase also helps push those vapors to that point.
just a curious observation / question..no concern whatsoever about those big fat tubes interfering with the intended design of the airflow...?? I mean they do appear to cover a decent percentage of the filter element, maybe completely insignificant or inconsequential....
While we're wondering, I've been wondering about the effect at the throttle body intake end of what I assume is a low-pressure atmosphere. In stock form, that little rubber hose comes from the two breather bolts and aims directly into the throttle body. When running, the engine is "sucking" air thru the filter, and also breathing through the little rubber hose. Is it reasonable to assume that the engineers calculated that low-pressure area to help the motor breathe? What might be the effect on breathing of taking the rubber hose out of the low-pressure region, maybe putting it outside the air-box, under the bike, and whatnot.?
pictures were just to show routing...all said and done the lines are tucked in a bit tighter and have no neg effects.plus thats a larger KN filter to start with...... But please dont do it if your torn....but take a peak in your air filter...than open your thottle body after 20 k...
Last edited by Bumpandrun; 06-17-2020 at 12:55 PM.
Bump that is a really clean setup. Thanks for sharing. Where did you route the hose down to?
my personal one just dumps under bike like my evo shovel twink for lots of years. But a few have concerns about oil on tire so i have run them back to end of swing arm. Think under bike works well ..as its like a old road draft tube on 50s model vehicles before EPA. Been trying different methods for years to dump it in exhaust...but none have worked great ....if only the moco could build us a good 4 stage dry sump pump with one stage being to scavenge cankcase pressure..the hp gains alone would be worth it...but EPA gets in the way of any real progress.
06-15-2020, 09:01 AM
