Purpose of Cylinder Head Breather Tube

maxwelljd · Post by **maxwelljd** » Sun Oct 21, 2012 2:13 pm

Hey All,

Sorry for the for the basic question...can someone explain what the purpose of the cylinder head breather tube is and if it needs to be connected to anything?

Thanks for everyone who's contributed here, it's a great resource.

kartgreen · Post by **kartgreen** » Sun Oct 21, 2012 2:26 pm

It's to relieve crankcase pressure ,normally it's connected to the air filter .

maxwelljd · Post by **maxwelljd** » Sun Oct 21, 2012 2:38 pm

Ahh I understand, didn't realize there was a passage that went all the way from the top of the engine, along side the cylinder, and down to the crankcase. Thanks!

Larzfromarz · Post by **Larzfromarz** » Sun Oct 21, 2012 3:14 pm

Normally its just a hose. Act like a PVC (positive crankcase ventilation) for 60's to 80's automobiles.
My CA160 filter has no provision so the case vents to the atmosphere under the bike.