Breather tube

[Guest Monty1952]

I think it's the breather tube that comes out just beside the side stand. Anyway for the first time I noticed today that I had a few drops of a black sticky tar like substance under the bike. It looks like it was coming from the breather tube and then drips down the spring on the side stand to the floor. Just had the bike serviced about 10 days ago and have probably only done about 250km since. Any idea what exactly this is as it's not oil consistency and doesn't smell like oil?

[Guest SpinyBiker]

Difficult to say without seeing where it is actually coming from.

My immediate thoughts, as I had something similar on a previous bike, is that it could actually be chain oil from your front sprocket. Two easy ways to tell.

1) dab your finger on the end of the breather tube you refer to (not sure which tube you refer to as the petrol tank overflow cones out that way) if there is a black sticky substance on your finger you know it is coming from the tube.

2) Have you checked behind the front sprocket cover? It can get pretty gummed up with chain oil fling and as such then runs down out to where you seem to be referring to. Just give it all a good clean and will soon stop.

Those are the two things I'd check anyway!

Edited October 17, 2016 by SpinyBiker

[Spindizzy 7,109]

Here, been discussed before.

 

http://www.nc700.co.uk/index.php?/topic/12786-breather-tube/?hl=breather

[Guest SpinyBiker]

Here, been discussed before.

http://www.nc700.co.uk/index.php?/topic/12786-breather-tube/?hl=breather

That topic refers to the crankcase breather, which if I have read the original post correctly above doesn't appear to be the one he is referring to as that isn't by the side stand. But as I say, difficult to say giving the fact we can't see what is actually being referred to.

The crankcase breather is a sealed tube.

Edited October 17, 2016 by SpinyBiker

[Guest Mac750]

Looking at my bike the crank case tube is by the rad and the battery breather tube is near the chain and side stand so it gets covered in chain oil and gunk.

[Guest Monty1952]

Here, been discussed before.

 

http://www.nc700.co.uk/index.php?/topic/12786-breather-tube/?hl=breather

Thanks but it's not the breather beside the rad that is plugged. It's an unplugged tube that is right beside the side stand.

[Guest Monty1952]

Difficult to say without seeing where it is actually coming from.

My immediate thoughts, as I had something similar on a previous bike, is that it could actually be chain oil from your front sprocket. Two easy ways to tell.

1) dab your finger on the end of the breather tube you refer to (not sure which tube you refer to as the petrol tank overflow cones out that way) if there is a black sticky substance on your finger you know it is coming from the tube.

2) Have you checked behind the front sprocket cover? It can get pretty gummed up with chain oil fling and as such then runs down out to where you seem to be referring to. Just give it all a good clean and will soon stop.

Those are the two things I'd check anyway!

Am thinking it's #2 above and will check that out tomorrow. I did put my finger on the tube I mention and it does have the substance I mentioned. Spray on chain lube does not have much odour and I would guess that on a recent long trip where I sprayed every other day it likely got gummed up. Did a major chain clean when I got back about a week ago. Is the tube (on my X) a breather from the sprocket cover?

[michael 324]

Thanks but it's not the breather beside the rad that is plugged. It's an unplugged tube that is right beside the side stand.

Some accumulated mung and drool from the countershaft sprocket (chain lube) occasionally drips down in that area…..??

(I spied my breather tube and found no oily substances coming from within it)

[Tonyj 6,907]

Chain lube

[embee 7,288]

There's a drain tube from the rubber apron round the fuel filler to drain any spills of fuel. Easy enough to check if it's this with some water.

[Guest SpinyBiker]

Am thinking it's #2 above and will check that out tomorrow. I did put my finger on the tube I mention and it does have the substance I mentioned. Spray on chain lube does not have much odour and I would guess that on a recent long trip where I sprayed every other day it likely got gummed up. Did a major chain clean when I got back about a week ago. Is the tube (on my X) a breather from the sprocket cover?

No it's not a breather from the front sprocket (no such thing), the tube is the drain from the rubber apron around the fuel tank opening. Definitely think it's chain gunk either overflowing from the front sprocket chamber or just flung from chain given you have said you sprayed every other day.

[CFB 4,601]

I agree it is chain lube running from the front sprocket cover.

Whip it off, clean with paraffin or other degreaser. While you're at it, take the chain guard and do the inside of that too.

You'll be surprised at the amount of gunk there is under there too.

[Guest Mac750]

No one said it's a breather for the front sprocket ??? It is a tube located by the front sprocket, where it can get covered in chain lube. I have not had the seat off to check the tank vent tubes, as yet, but it is directly under the battery area and is the same dia as every other battery vent tube I have ever seen on any Honda I have ever owned. So it wouldn't be beyond the possibility that the tube was ether a battery vent tube or a tank vent tube. Ether way it's give it a clean and not worry about it.

[Guest Monty1952]

There are actually two breather tubes down close to the front pegs and side stand area. I live in a condo with underground parking that's not so well lit. Will take to a friends garage soon with better lighting and check origin of tubes but in any case I am fairly sure it's from the front sprocket and gunk thrown from chain. Likely some of the solvent recently used in cleaning loosened s**t around the sprocket housing that gradually made its way down breather.