Author Topic: Line Identification  (Read 418 times)

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Offline theslayedsaint

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Line Identification
« on: March 02, 2015, 09:38:49 PM »
looking at item 10 on fetch photo.
So i have a picture from when i removed this and it seems like everything says its a "breathing" line but i'm trying to understand why it goes from the engine to the oil tank and what is its use. also what type and size hose do i use? the other question is what is the hose on the top of the oil tank? is it just a breathing hose for the oil tank? or a over flow?
1974 CB750 custom build cafe racer
-849cc big bore
-Webcam 63a
-APE rods
-4-1 stainless exhaust
-GSXR front end

Offline mystic_1

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Re: Line Identification
« Reply #1 on: March 02, 2015, 11:34:05 PM »
Oil vapor (from pumping oil back into the oil tank) is precipitates in a breather chamber inside the tank, runs down the lower "breather" line and is returned to the engine via the fitting at the rear of the crankcase.  Part of this lands on the auto-oiler catch tray and lubricates the chain, the rest drains into the engine.

The larger line near the top of the tank allows for pressure equalization inside the tank and is vented to atmosphere near the center stand pivot.

mystic_1
"A ship in harbor is safe, but that is not what ships are built for."
- John Augustus Shedd

My build thread:  http://forums.sohc4.net/index.php?topic=68952.0

Offline theslayedsaint

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Re: Line Identification
« Reply #2 on: March 03, 2015, 11:12:38 AM »
thanks thats what i was thinking thats for clearing it up for me.
1974 CB750 custom build cafe racer
-849cc big bore
-Webcam 63a
-APE rods
-4-1 stainless exhaust
-GSXR front end