Author Topic: 500 cylinder head cover breather tube route?  (Read 968 times)

0 Members and 1 Guest are viewing this topic.

Offline Chachi

  • Hot Shot
  • ***
  • Posts: 713
500 cylinder head cover breather tube route?
« on: July 13, 2012, 07:24:10 pm »
There are some old threads about this, however I am still looking for clarification.

(http://forums.sohc4.net/index.php?topic=73248.0)

My cylinder head cover breather tube routes down with all of my other tubes (carb overflow, battery, etc.). It does not connect into the airbox as I think the 550 does. My airbox has its own breather tube that also routes down with everything else.

The issue is that the routing or length of my cylinder head cover breather seems to be a few inches too short. Instead of emitting vapors out into the air, they collect on the bike which is hot and the vapors smoke. Not much, but enough to be annoying.

What should the tube route be? Does the cylinder head cover breather tube fall shorter than all of the other tubes? Is there a graphical diagram of tube routing for the 500?

Thanks.
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1

Offline dave500

  • Really Old Timer ...
  • *******
  • Posts: 16,949
  • WHAT?no gravy?
Re: 500 cylinder head cover breather tube route?
« Reply #1 on: July 13, 2012, 07:28:03 pm »
it should reach below the engine somewhat,it dumps in a stupid spot right in front of the rear tyre?forward motion is supposed to draw the fumes out of the tube.

Offline Chachi

  • Hot Shot
  • ***
  • Posts: 713
Re: 500 cylinder head cover breather tube route?
« Reply #2 on: July 13, 2012, 07:40:36 pm »
I think if mine was a few inches longer it wouldn't collect and smoke. And yeah it's when I'm sitting still that it starts collecting/smoking. Solution: don't sit still I guess.
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1

Offline dave500

  • Really Old Timer ...
  • *******
  • Posts: 16,949
  • WHAT?no gravy?
Re: 500 cylinder head cover breather tube route?
« Reply #3 on: July 13, 2012, 08:21:50 pm »
its for fumes and mostly water vapour,a badly worn engine could have so much piston blow by that the pipe actually smokes.

Offline Dimitri13

  • Not a
  • Master
  • *****
  • Posts: 1,603
  • 1974 CB550K
Re: 500 cylinder head cover breather tube route?
« Reply #4 on: July 13, 2012, 10:15:56 pm »
Mine has a steady stream of smoke and some oil droplets. I've routed mine under my battery. It hits the inner fender and not the tire.

Offline lucky

  • Really Old Timer ...
  • *******
  • Posts: 6,717
Re: 500 cylinder head cover breather tube route?
« Reply #5 on: July 13, 2012, 10:38:30 pm »
There are some old threads about this, however I am still looking for clarification.

(http://forums.sohc4.net/index.php?topic=73248.0)

My cylinder head cover breather tube routes down with all of my other tubes (carb overflow, battery, etc.). It does not connect into the airbox as I think the 550 does. My airbox has its own breather tube that also routes down with everything else.

The issue is that the routing or length of my cylinder head cover breather seems to be a few inches too short. Instead of emitting vapors out into the air, they collect on the bike which is hot and the vapors smoke. Not much, but enough to be annoying.

What should the tube route be? Does the cylinder head cover breather tube fall shorter than all of the other tubes? Is there a graphical diagram of tube routing for the 500?

Thanks.

You can get a breather /separator from any motorcycle that same size and use it.

Offline dave500

  • Really Old Timer ...
  • *******
  • Posts: 16,949
  • WHAT?no gravy?
Re: 500 cylinder head cover breather tube route?
« Reply #6 on: July 13, 2012, 10:49:45 pm »
zip tie a rag to the end of the pipe if its getting messy.

Offline Chachi

  • Hot Shot
  • ***
  • Posts: 713
Re: 500 cylinder head cover breather tube route?
« Reply #7 on: July 14, 2012, 08:16:20 am »
Is there a good source for pics of stock tube routing? My shop manual download has a diagram of the 'new features of the 550' where the breather routing/connection was changed compared to the 500, but I can't seem to find info on the 500 set up.

There are some U shape tube collectors (welded to frame by center stand) which I assume is where I gang some of the tubes up to route down. I'm curious which tubes should be routed where.

To solve the smoke annoyance I can try to reroute or possibly degrease all of the built-up collection of stuff off of the frame (down near center stand). If I keep on top of that it probably won't generate enough to smoke.
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1

bollingball

  • Guest
Re: 500 cylinder head cover breather tube route?
« Reply #8 on: July 14, 2012, 03:41:19 pm »
Just get a longer hose and zip tie it any where you want nothing special about it. You might be over thinking it.

Offline Chachi

  • Hot Shot
  • ***
  • Posts: 713
Re: 500 cylinder head cover breather tube route?
« Reply #9 on: July 18, 2012, 07:36:55 am »
I realized my breather tube was routed in front of the swingarm vs. over it and behind it. All of my other tubes route down in front of the swingarm and they have enough length to flow anything out to the ground and not collect on the bike (carb overflow, airbox breather, battery).

The cylinder head breather tube did not have enough length to clear the bike in that routing configuration. By taking it over the swingarm and routing down behind it anything that comes out will hit the inner rear fender or rear tire and shouldn't generate smoke. It was routed in front of the swingarm when I got the bike. Am I correct that it is supposed to route over and behind the swingarm as outlined above?
73 CB750 K3
72 CB500 K1 - Sold
75 MR50 Elsinore K1