Topic: What's it?

[Chris Schneiter]

There is a rubber tube that comes out near my rear axle, behind the muffler on the right hand side ('76 750 K6)..I had always assumed that it was an overflow tube.
Yesterday, I started up, let it run for a while so it was good and warm, then rode it for about 10 minutes. When I got back, I looked down and there was white vapor coming out of it!
It's been sitting for about 3 weeks (while it snowed), and it was about 50º when I rode. Could it be water vapor? I've never seen it before. Also, what is the tube? I'm taking it to be a breather tube, but I didn't think '76s had them?
Any info would be appreciated.

[736cc]

Theres 2 different breathers that unceremoniously dump out the back of the CB750's; 1 from the top of the oil tank, the other from the cam box. Trace your hose to find out which.
Water vapor heating up inside hose likely.

[Chris Schneiter]

I just went out and rode a little...I think this one's from the top of te motor..still steaming..It's been outside in a carport, covered, but in the snow..last week, I came home to find that I hadn't covered the end of the pipes, and the muffler was packed with snow! Possibly some got into the breather hose too, and maybe I'm burning off some condensation from sitting in the cold..