breather/air box modification ???

rsylvstr · Full Member Joined: Aug 09, 2008 Posts: 65

I read multiple posts and hope i got this right. It's for a 1981 XS650SH. sorry i didn't mark the pics, but i think they are self explanatory. I am doing this because the way i understand it after reading the posts, the stock set up sends (possibly) oil mist into the air box ahead of the filters and then they get directly sucked into the carbs leading to an even richer condition.

I removed the T-fitting along with the two hoses that went to each airbox. and then i attached the Purolator breather filter to the hose coming down from the top of the engine.

am i just piddling around or did i understand the posts correctly?

I just looked at 5twins post and realized that i need vacuum???? and to use a power brake check valve instead of the breather filter????
Thanks.

5twins · Full Member Joined: Aug 05, 2006 Posts: 1616

You don't need the vacuum. It's just the latest little mod some of us are doing. Creating a slight vacuum in the crankcase is supposed to help prevent oil leaks and if you already have some, make them leak less.

rsylvstr · Full Member Joined: Aug 09, 2008 Posts: 65

thanks for the prompt reply...haven't had this on the road yet, so unsure how/if she'll leak. does have a case leak i have to track down...probably from the PO's shop changing the sump filter (if they did)

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