Where does the cam top cover vent pipe connec to?

[McCabe-Thiele (Ted)]

As I was working on my 400 with the petrol tank off doing some minor fettling I decided to fit a clip on the top vent .

I found a nice spring clip but somehow managed to pull the pipe out of wherever it fits, can't remember where it goes to at the other end?

Is it to the side outlet on the plastic bottom item that is fixed to the air cleaner case?
That will be fun if it is.

[Herr Supersport]

Sir

So it is - should be possible to reinstall. With small fingers.
Let's see if I can add a picture

[McCabe-Thiele (Ted)]

Thanks for that, you can barely see the unit through the frame after  a lot of expletives I cheated. I managed to fit a length of new pipe using some special pliers onto the air filter box fitting. I used a 90 deg bend and joined the pipes. Next time the tank is off I will fit a single pipe.

[Athame57]

I hunted high and low all over the planet for the plastic bowl one fits below the air box. Then I saw one staring at me on the 400four bits site, it cost me a fiver. I found setting up it's gasket the hardest. I have since disconnected the whole thing again because it fouls up the air filter.  The whole idea of fitting it in the first place was to get it past US emissions requirements I gather. Mine now lurks in the bottom of my spare parts box.  By the way, Julie sells the little square sponge one fits for it in the bottom of the airbox.

[TrickyMicky]

I hunted high and low all over the planet for the plastic bowl one fits below the air box. Then I saw one staring at me on the 400four bits site, it cost me a fiver. I found setting up it's gasket the hardest. I have since disconnected the whole thing again because it fouls up the air filter.  The whole idea of fitting it in the first place was to get it past US emissions requirements I gather. Mine now lurks in the bottom of my spare parts box.  By the way, Julie sells the little square sponge one fits for it in the bottom of the airbox.

Aha!! A man after my own heart. My 400 is a bit of a 'heavy breather' after all these years, does not use any oil at all, but it does require renewal of a smelly air filter now and then. We all know that the professional cure is engine out, and strip down. Sorry, but I am too old for that now, and I want to continue riding it whilst I'm still able, so was thinking of converting it to old fashioned 'smog specification' with the breather pipe venting direct to atmosphere somewhere near the rear chain. I don't think my minimal mileage will affect the atmosphere too much compared with looking at the Flight Radar website and seeing the astronomical amount of crap being emitted at any one time above our heads

[Rozabikes Tim]

Back in the day the racing lads used to feed it into a coke can or similar cable tied to the frame.
That would mess with your lovely restored bike's look.😱

[florence]

certainly, earlier bikes, such as my 350K, had the tube going to the atmosphere and never presented a problem.

[McCabe-Thiele (Ted)]

One of the things that actually worked was when the BL A series engine introduced positive crank case ventilation with the oil precipitator on the push rod side case and a vacuum operated valve that vented into the air cleaner box. It seemed to prevent the build up of black sludge in the oil - that was probably mainly fixed by better multi grade mineral oils.

I have no idea if modern motor cycle engines use such devices.