breather vs non-breather heads

[mystryman]

I have a '98 fxdwg. heads went bad. I bought a set of rebuilt heads from an auction and when I got them, found they were non-breather heads. will they work on my motor that had breather heads on it? Or in other words, is the head to head oil breather tube important?

 

[Blew]

The head breather are needed, but from memory you can modify the non breather heads to breathing type.

 

[fin_676]

As the piston goes up and down then air needs to move in and out of the crankcase to fill the vacuum that would otherwise occur with piston going up when the piston goes down then the air under it needs to move out of the way or the crankcase would pressurise
so the breathers are really important so you need to have them older evo models had the breather directly in the crankcase just behind rear cylinder

Brian