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Engine Mechanical TopicsDiscussion for motor builds, cams, head work, stripped bolts and other engine related issues. The good and the bad. If it goes round and around or up and down, post it here.
First pic is out of 09 service manual - the rest is what i actually have
Has mine been changed or upgraded ? checked ronniesonline and all 08-09 and 10 are the same as the parts book pics
So seeing that little umbrella valve is like a check valve not allowing the gases back into the exhaust . Is this just a cheap way to bypass the exhaust from returning it back to the intake ?
No, it's a check valve to not allow contaminants back into the crankcase. Remember these breathers are for releasing crankcase pressure. Helps to keep your gaskets and seals from leaking.
can you run without it??? sure, was done for decades on engines.
is it important??? well
it prevents atmospheric air back into the c/c which will reduce condensation and cleaner oil
it helps create a vacuum in the c/c which helps increase power
it helps in oil control on the piston assy
it helps oil flow as hd engines uses this diff'l pressure to move the oil from the flywheel area
awhile back, i think hd got rid of the packing since it had a tendency to clog. most of the oil is removed by the labyrinth chamber.
If the engine had external check valves (Doherty, ET, S&S....) you remove the internal ones.
Thanks where would you look , when i purcasedthe bike it had the stock oval 96 air cleaner with stock breather bolts so im thinking there were no extrenal anything installed ???
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Breather ????
