What to do with these air filter intake holes?

[Niels Mouthaan]

I noticed these intake holes in my air filter and they seem to bypass the filter itself. The previous owner seem to have closed them provisionally using caps but I guess I lost one. The bike runs fine though. However, I don't like the fact the filter itself is partially bypassed.

What is the purpose of these holes? What should I do with them? Should I simply close them both and if yes, what original part is used for this?

Thanks guys!

 

[aldo5468]

They connected via a T fitting to the oil breather outlet. Plug the open one.

 

[5twins]

Yes, they are for the breather hose that comes off the back of the motor. They recycle any oil vapor emitted by the breather back through the engine. Personally, if I had them, I would use them (I don't, I run pods). Here's a drawing showing the parts you're missing #19 - 23 .....

http://www.boats.net/parts/search/Yamaha/Motorcycle/1981/XS650H/CYLINDER HEAD/parts.html