Haynes manual part #41 pg 23 image. Help!

[Gem State Outlaw]

1975 xs650B: So I've got a part called a "breather plate" this is listed as part #41 on page 23 of Haynes manual. Slides into the back of the head above the cam tensioner. I think the function is to assist drip oil onto the cam tensioner head pin but not certain. The question is do I need it or can it be left out without any problems. Pic of the part below.

 

[retiredgentleman]

That piece is there to allow air/oil mists to move in and out of the crankcase, but to stop heavy oil drops. It functions as a labrinth..........light density passes through but heavy density does not.............oil falls down into the sump.

Yamaha put it there for a reason, so yes it should be there. Will it work without it..........sure it will, but you may have excessive oil coming out the breather tube/s.

 

[Gem State Outlaw]

Thanks RTG! Much appreciated

 

[Classic]

Will it work without it..........sure it will, but you may have excessive oil coming out the breather tube/s.

And it seems like every day someone seems to complain about that.

 

[retiredgentleman]

That part #41 is very effective at stopping oil from exiting the crankcase. My engine has that part, and my 2 breather hoses go into my stock 2 airboxes. Any oil mist is reburned by the engine.

When I inspect the area in the airbox, where the mist enters, there is never any oil present.

If you find oil present, it means you have worn engine internals (rings).