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While doing the winter maintenance, I re-read the schedule and realized I skipped this item in the past. I have 7500 miles on the bike, so I checked this tube. Like many others who posted about this, mine was dry anyway. The 4k mile interval seems awfully short for something like this. It wouldn't be a pain to check except that I have the Kury highway peg to remove before I can get the head cover off. Of course, after going through this trouble once, I see now that I can inspect the tube without removing the cover. I will do this from now on.

It got me thinking about why this tube is plugged in the first place. I concluded that it must pull a vacuum when the engine is running and they don't want it sucking up debris (?). I was wondering if I could replace the plug with a two dollar automotive PCV valve. That way it would act like a plug when it pulls a vacuum, and self-draining when the motor is off. That would eliminate one maintenance headache. Thoughts?
 

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The hose that has the plug in it goes directly to the air box (after the air filter). If you were to remove the plug and start the engine, it could potentially suck up dirt or sand and it would go directly into the engine. The plug needs to be in place to prevent dirt ingestion and engine damage.

If you ride in the rain a lot, you will probably find watery gunk in this hose. It is meant to be a water drain for the air box and should periodically be emptied.
 

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Fred, if I followed his point, he acknowledged that there is probably a vacuum on the hose while running, hence the plug, however, he posed that the PCV valve would close while running (taking the place of the plug) yet would drain when the engine was stopped. If that is true, then it seems that you would want to move the end of the tube, otherwise, it would drain into the head cover. So the question seems to be a good one. Looks like the end could be moved so that it could drain into the lower cowling.

This raises another question: Why would Honda terminate this drain tube in the head cover instead of next to the evaporation cannister, for example? Could it be heat?
 

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gpick said:
Fred, if I followed his point, he acknowledged that there is probably a vacuum on the hose while running, hence the plug, however, he posed that the PCV valve would close while running (taking the place of the plug) yet would drain when the engine was stopped. If that is true, then it seems that you would want to move the end of the tube, otherwise, it would drain into the head cover. So the question seems to be a good one. Looks like the end could be moved so that it could drain into the lower cowling.

This raises another question: Why would Honda terminate this drain tube in the head cover instead of next to the evaporation cannister, for example? Could it be heat?
My worry with doing this is that the liquid crud that comes out of the end of the hose would likely clog the valve and cause it to stick open. I thought about installing a small sealed catch bottle on the end of the hose just to make it easier to empty, but I never seem to find anything in the hose anyway so I never did it.

I did recently take the plug off the end of a bike that gets ridden in the rain ALOT and it had quite about half a cup of black goey junk that came out the end.
 

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Agree, the PVC valve would not be as reliable and its not that hard to check so long as you don't follow teh Honda instructions RE removeing the cover.

prs
 

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Since the breather hose on the Wing is connect to and meant to drain the airbox, I doubt there is much vacuum available. PCV valves are meant to be connected to the intake manifold of an engine and are closed during periods of high vacuum such as idling or cruising. The PCV valve opens during periods of low manifold vacuum such as full throttle or climbing hills and allows excessive crankcase blowby gases to be drawn into the engine and consumed. I really doubt there is ever anywhere near enough vacuum in the airbox of the Wing to hold a PCV valve closed as desired in this case.

I think that maybe the tube is run into the head cover area so that normal engine heat will evaporate some of the moisture back up the tube to be drawn into the engine, and allow the concentrated crud to be left behind at the bottom of the tube. JMHO
 
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