Topic: Lonely hose seeks connection

[MosquitoJones]

I got brave today and decided to check my valve clearances.  While I was looking around, I found this:


I thought at first it was some type of vent/overflow hose for the gas tank, but that wasn't it.  There wasn't a second connection to the tank.  Then while I was meditating on my carbs, I saw this:


Are these two long lost loves?  Do they belong together?  The connector in question is a t-junction between two of the carbs.  By the look of the hose it hasn't been freshly disconnected from anything.  If a reunion is in order, I will do the appropriate matchmaking, complete with flowers and Barry White.

[gold72]

cant help you out with the tubes, but I like the Barry White and flowers call

[kslrr]

Does the engine run well with these lines disconnected?

Do you now or did you once have a vacuum actuated fuel petcock?

Or, it might be part of the emissions system.  My '81 CB650 had all that stuff removed by the PO, so I have no reference to look at except what I have seen in the manual.

[MosquitoJones]

I've been having some trouble with the engine keeping up at freeway speeds, and some backfiring as of late.  As far as the vacuum petcock, I have no idea.  I am the second owner on the bike and have not replaced the petcock.  There is only one hose connection on the petcock, and that for the fuel line.  AFAIK the bike is stock, except for new handlebars I put on it about a month ago.

[Gordon]

Many otherwise helpful members tend to just ignore tech questions when the model and year of the bike in question isn't posted.

It can get kind of old constantly typing "what bike?". 

[WFO]

What kind of bike is it?

[super pasty white guy]

I'm guessing it's the '82 cb650.  But then I've been wrong before.  Repeatedly.

spwg

[WFO]

What are the other ends attached to?

try this link to maybe find a picture

http://forums.sohc4.net/index.php?topic=17788.0;topicseen

[kslrr]

Many otherwise helpful members tend to just ignore tech questions when the model and year of the bike in question isn't posted.

It can get kind of old constantly typing "what bike?". 

If you look at his signiture, it states '82 CB650.  Some members don't look beyond the post. jk

[Gordon]

If you look at his signiture, it states '82 CB650.  Some members don't look beyond the post. jk

Some members have checked the option to turn off other member's signatures because some members insist on putting large pictures and/or banners in their signatures that other members don't necessarily feel like looking at and scrolling past multiple times in one thread.    Besides, just because there is a bike mentioned in someone's signature doesn't automatically mean that's the bike in question.

[Hush]

On my 650 that would be the breather from the rocker cover to the air filter box, there aint much that uses such thick tubing but you say the T junction goes to 2 carbs?
Maybe in some past life the bike had a petrol tank over flow or balancer tube?
Try attaching an old piece of tubing of smaller guage and blow down the damn thing!
If that is supposed to attach to your carbs and it is not connected you can expect some form of penalty.
Oh yeah and now you have the tank off, a squirt with the hose to remove all that horrible dust might be in order.

[MosquitoJones]

Hurr, sorry.  My only bike is in my sig, which is an '82 CB650.  I know it's not the breather, since that was still firmly attached.  Mystery hose runs down through the center of the bike.  I'm beginning to suspect it might be some kind of fuel overflow hose for the carbs, or as was suggested, a balancer of some kind.

Hush, if you think the dust is bad, you should see the gunk in there.  I have what I thought was the infamous head gasket leak, but I cleaned up engine a bit yesterday and today it appears that the leak is coming from the top of the engine where those valve covers sit.  I'm relieved, since I imagine it will be much easier replacing that gasket than removing the head.  But the engine is in dire need of a really good scrubbing with simple green.  I think this winter I will be taking the engine out and going over the whole thing.  Lord help me.

[WFO]

Dowload those free manuals i posted.

[MosquitoJones]

I bookmarked it, no printer at home.  I will abuse the ones at work in the upcoming week    Also, I didn't see the mystery hose in the manual, it may have been an option or something the PO installed.

I had already downloaded the CSM but I didn't see anything listed in it either.

[WFO]

Ok heres the cb650 shop manual it's showing different carbs?

http://cosky0.tripod.com/imagelib/sitebuilder/misc/show_image.html?linkedwidth=actual&linkpath=http://cosky0.tripod.com/sitebuildercontent/sitebuilderpictures/page04-00-fuel-system.jpg&target=tlx_new

your carbs look just like the ones on my 82 cb650sc nighthawk it has VB carbs like you picture.

yours must be a cb650c  right?

http://www.myhonda650.com/cb650history.htm

[eurban]

The 82 650s have a surface mounted fuel cap without any trap door so those hoses are certainly not fuel overfill tubes running from the tank.  The carb overflow tubing is much smaller diameter and will be mounted on the nubs on the bottom of the bowls so those hose are not carb overflow.  The vacuum operated fuel safety device that someone mentioned earlier is a separate item than the petcock.  It will have a fuel hose going to it from the petcock, and then a fuel hose running down to the carb bank.  It will also have a small diameter vacuum hose connected to it.  It is typically mounted to the top of the carb rack.  Those hoses are most certainly not related to it.  That leaves carb air pressure balancing tubes and crankcase ventilation / rebreather tubes as the only options.  You can follow the crankcase tube from the back top of the engine.  The larger tube that is closer to the engine in your pic looks like it is the the crankcase breather tube.  It should run towards the back of the bike and connect into a separator container.  Once the spooge is separated out a hose then runs to the air cleaner housing to breathe back the crankcase fumes.  The T with the missing tubing looks like carb balancing stuff.  Perhaps the smaller tube farther away from the engine connects to the T.    If all the parts are there and if they are all stock then it should be somewhat obvious how things are supposed to go back together, simply by judging the lengths of tubing and number and size of empty fittings.  If its doesn't seem to make sense by carefully looking at things on the bike, look at the parts fieches for the carbs and for the emissions control stuff for your year bike and you should find some useful info.  There are a number of online stores that allow you to pull up parts diagrams. www.powersportspro.com is one of them.  Good luck

[MosquitoJones]

By that link you posted WFO, mine must be a 650B.

Manufactured 10/81
VB44ABTJ7 carbs
Engine# RC03E-2304755

I guess the solution here is to take the tank back off and get more pictures.  Just to clarify, in that first picture, the hose in question is rather centered in the picture.  The disconnected hose on the left side of the picture is the fuel line.

Edit: eurban's parts fische shows the t-connected hoses to be carb vent hoses.