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standard cx500 1980
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Discussion Starter · #1 ·
hi all, i'v seen some photos of cx engines with the breather hole blanked off with a cap, can someone please tell me how this works, ie where does the engine breath from when this hole is blanked off ?
 

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Not all CX500s used the bottle breather fitted to the timing inspection port. Early cx500s had breathers in the cylinderheads. The GL series had the breather in the timing cover on the back of the engine.
 
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'84 CX650E that is evolving into a GL500
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To clarify: The actual breather ports on your 1980 CX500 should be hose barbs on the cylinder heads to which short bent pieces of hose are connected. Those hoses meet at a T fitting and another hose from the T runs to the airbox.

Models with Transistor Amplifier Ignition (GL500, CX500E, all CX/GL650) have one hose barb for the breather and it is on the timing cover.

Some models in some markets also came with the so-called "bottle breather" that screws into the timing mark port on the right side of the engine's rear cover in place of the normal cap as a secondary port in addition to the normal breather ports on the heads or timing cover.

If you were to block your engine's breather ports pressure from blowby (combustion gasses that make it past the piston rings) would pressurize the crankcase and eventually escape through whichever oil seal it could (when the breather on mine iced up one winter day oil sprayed out of the shift shaft seal and soaked my left leg).
 
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