Are there any "upgrades" or better ways to vent the breather on a CB500? Mine just has the open hose that goes down behind the engine.
The "better way" was introduced on the CB550. I don't see why you couldn't fit the filter box onto the earlier model, to make both the machine and all life breather easier.
A breather filter for the end of it?
Does nothing except keep bugs from crawling up the tube into the crankcase of the engine.
Vented back to the air box some how?
That's exactly what the 550 upgraded filter box does.
Leave it as Honda intended?
Not for the informed, enlightened, or environmentally conscious.
A Reed type PCV valve?
PCV stands for Positive Crankcase Ventilation. It applies to engines that have TWO crankcase fittings. One to supply fresh air (often filtered), and one to provide evacuation of the crankcase gasses and vapors. A valve is usually placed in the vacuum source path to shut off or restrict ventilation when manifold vacuum is very low. The systems I am familiar with, tap into manifold vacuum between cylinder and carburetor.
As the SOHC4 only has one Crankcase fitting, the choices are really only venting or Positive Evacuation. Honda chose Positive Evacuation for almost all the Cb550s.
Simple venting allows the expanding gasses/vapors to escape without building up pressure inside the engine.
Evacuation helps lower the boiling point of water (which helps eliminate condensation buildup faster, helps seal piston rings to lessen blow by, and scrubs both these pollutants and the oil vapors using the high heat combustion chamber of the engine. It's a win-win for a few extra passive parts.
If you keep to a proper schedule of cleaning/clearing the small foam element that is part of the recirculator assembly, and don't run 649 carbs with the required inlet restrictor pictured below, there is no fouling of the paper filter element in the stock CB550 filter box, (until the element is already clogged with outside dust and needs to be replaced anyway).
Cheers,
