What is this one?

[darkangel_imp]

Hi all, tonight after a riding, I was looking around the bike and see this part (image attached), could anyone tell me what it is? Should I open and clean it because it looks dirty. Thanks!

 

[Cormanus]

darkangel, my Honda manual calls it a crankcase breather tube. There's another one under the engine on the left hand side of the bike. You need to empty it if it fills up. It's pretty easy to do, although I'm blowed if I can ever manage it without getting gunk all over the top of the crank case.

I find the easiest way to do it is to take the circlip off the top and take the whole pipe off rather than fiddling with the plug on the bottom. That's probably why I make a mess.

 

[mininsx_imp]

I check mine every time I do an oil change. There's usually nothing in them.

 

[Lord Popgun]

darkangel, my Honda manual calls it a crankcase breather tube. There's another one under the engine on the left hand side of the bike. You need to empty it if it fills up. It's pretty easy to do, although I'm blowed if I can ever manage it without getting gunk all over the top of the crank case.

I find the easiest way to do it is to take the circlip off the top and take the whole pipe off rather than fiddling with the plug on the bottom. That's probably why I make a mess.

Hey Cormanus, is your crankcase made of plastic and mounted right under the tank ? That one is for the airbox or cleaner or whatever you want to call it.

 

[Nortoon_imp]

Since we are looking at unusual engine parts. Does the oil drain plug on the CB1100 face straight down?

The reason I ask is the oil drain plug on the CB500XA I own faces backwards. If you undo it, hot oil sprays all over the center stand, rear wheel, and garage floor. None of it makes it into the oil drain pan under the bike. I had to buy a Fumoto oil drain valve to cure the problem.

 

[Lord Popgun]

Since we are looking at unusual engine parts. Does the oil drain plug on the CB1100 face straight down?

Yes. Look at this: Item 22 http://www.hondapartshouse.com/oemparts/a/hon/511a8d7cf870022e4ccd3241/oil-pan-oil-pump

Oil drains into a pan very nicely

 

[the Ferret]

How To do your own 600 mile service

 

[AzBob_imp]

darkangel, my Honda manual calls it a crankcase breather tube. There's another one under the engine on the left hand side of the bike. You need to empty it if it fills up. It's pretty easy to do, although I'm blowed if I can ever manage it without getting gunk all over the top of the crank case.

I find the easiest way to do it is to take the circlip off the top and take the whole pipe off rather than fiddling with the plug on the bottom. That's probably why I make a mess.

Hey Cormanus, is your crankcase made of plastic and mounted right under the tank ? That one is for the airbox or cleaner or whatever you want to call it.

Hey Cormanus, is your crankcase made of plastic and mounted right under the tank ? That one is for the airbox or cleaner or whatever you want to call it.
The PCV system vents to the airbox to re-burn stuff to meet EPA emissions standards, so yes, it's still a crankcase breather tube because that's where the PCV stuff originates.

 

[Lord Popgun]

OK, thanks AZbob! That makes perfect sense. I like my plastic crankcase theory better though

Standing by for abuse from Cormanus (deservedly so)

 

[Cormanus]

I'll let you off popgun. As you'll see I said "my Honda manual calls it a crankcase breather tube". I said that because it seemed odd to me that it would be sticking out of a part above what I always thought was the crank case.

So thanks, AzBob, now I understand better.

Mine, by the way, is often full.

 

[Nortoon_imp]

How To do your own 600 mile service

Thanks gentlemen! That what I am use to seeing.

The rearward facing drain plug on my CB500XA was a real messy PITB.

 

[darkangel_imp]

darkangel, my Honda manual calls it a crankcase breather tube. There's another one under the engine on the left hand side of the bike. You need to empty it if it fills up. It's pretty easy to do, although I'm blowed if I can ever manage it without getting gunk all over the top of the crank case.

I find the easiest way to do it is to take the circlip off the top and take the whole pipe off rather than fiddling with the plug on the bottom. That's probably why I make a mess.

Cormanus, thank you so much! So I'm confidence to open and clean it now :excited:

 

[dave]

Darkangel - have you had your engine oil temperature sensor (EOT) replaced? From your picture it looks like there has been a wrench on it. Can you provide any details if you have? Thank you.

 

[darkangel_imp]

Darkangel - have you had your engine oil temperature sensor (EOT) replaced? From your picture it looks like there has been a wrench on it. Can you provide any details if you have? Thank you.

Hi Dave, I didn't touch that EOT. Mine is 2014 DLX, what's about yours? Could anyone show their EOT for double check? Thanks!

 

[jimgl353_imp]

whatever that thing is, it is corked off, doing absolutely nothing. looks like another of those parts related to the plug in the air intake snorkel, that is maybe used in another country, but not here... so it's just capped off. take it off, toss it and put a tidy little rubber cap directly on it and be done. it would be a crank case breather tube if it were in use, but it's not.

 

[curlyjoe]

On page 1-31 of the 2013 service manual is a brief description and diagram of the crankcase emission control system. Blow-by gas is returned to the front air cleaner housing and thus is "recycled" into the throttle body. It's a closed system to prevent discharging crankcase emissions into the atmosphere.

Over time, fluids accumulate in the front and rear air cleaner housings. The picture in post one of this thread is the drain tube for the front air cleaner housing. The capped drain tube under the bike is for the rear air cleaner housing, See page 3-6 of the 2013 service manual. The manual calls them crankcase breather tubes but they are simply drain tubes for fluids that accumulate in the front and rear air cleaner housings. They need to be capped to prevent air intake that bypasses the air filter.

Let me know if any of this is inaccurate as it's my interpretation of information in the service manual.

 

[Lord Popgun]

They are just drains, even though Honda labels them funny.

In that pic on page 1-31, the recirc is by that hose at the top. If you go look at your bike between the throttle bodies and the airbox, up under the tank, you can see that hose. Its a fairly big one.

Not the pair hoses. It is in the center of the valve cover. Check out pages 7-6 bottom pic and 7-7 pics. The bottom pic on 7-7 shows the port nipple clearly.